光コムによる表面形状計測技術-非接触インライン全数検査を目指して
塩田 達俊
Volume：P2411-06, First page：7, Last page：16, Feb. 2025
Calibration method for spatially resolved tomographic spectroscopy based on a time-domain interferometer
Masaya Sakatsume; Bao Dinh Thai; Tatsutoshi Shioda
Optics Communications, Volume：574, Number：13, First page：131180, Jan. 2025, [Reviewed]
Nonlinear polarization rotation based 635 nm praseodymium doped mode-locked fiber laserNasrin Sultana; Masanori Nishiura; Tatsutoshi Shioda
Applied Physics Express,
Volume：17,
Number：11,
First page：112002, Nov. 2024,
[Reviewed]Abstract
We demonstrated a mode-locked fiber laser oscillator using nonlinear polarization rotation as a saturable absorption system. The fiber laser generates mode-locked pulses by adjusting four waveplates. A single-clad Pr
3+-doped single mode fluoride fiber with a 425 mW threshold pump power serves as the foundation for the ring cavity, which operates in the dissipative soliton resonance regime. The radio frequency signal-to-noise ratio of the pulses at 634.9 nm is 60 dB, maximum output power of 5.5 mW, and repetition rate of 34.5 MHz. These findings provide a foundation for the advancement of photonic applications in the visible spectrum.
IOP Publishing, Scientific journal
DOI：https://doi.org/10.35848/1882-0786/ad8a15DOI ID：10.35848/1882-0786/ad8a15,
ISSN：1882-0778,
eISSN：1882-0786 低コヒーレンス光周波数コムを用いた機能的形状計測システム
塩田 達俊, 崔 森悦
Volume：53, Number：2, First page：65, Last page：71, Feb. 2024, [Reviewed]
Nanometer resolution of 2D single-shot low-coherence & comb-based profilometry based on the effect of discrete height of spatial phase modulator surface
Bao Dinh Thai; Keishi Chiba; Tuan Truong Cong; Tatsutoshi Shioda
Optics Communications, Volume：546, First page：129802, Nov. 2023, [Reviewed]
Efficient use of all ports of a 3 × 3 coupler in a nonlinear amplifying loop mirror-based fiber laser
Masanori Nishiura; Ryo Kageyama; Tatsutoshi Shioda
Optics Letters, Volume：48, Number：16, First page：4312, Last page：4315, Aug. 2023, [Reviewed]
Wavelength and pulse width programmable mode-locked Yb fiber laser
Masanori Nishiura; Tatsutoshi Shioda
Optics Express, Volume：31, Number：4, First page：5347, Last page：5362, Feb. 2023, [Reviewed]
Systematic 1D electric field induced second harmonic measurement on primary-to-secondary transition phase of positive streamer discharge in atmospheric-pressure air
Yuki Inada; Tatsutoshi Shioda; Ryosuke Nakamura; Mitsuaki Maeyama; Akiko Kumada; Shin Nakamura; Ryo Ono
Journal of Physics D: Applied Physics, Volume：55, Number：38, First page：385201, Jul. 2022, [Reviewed]
Improvement of optical setup of the novel 2D single-shot comb-based interferometer for high-resolution measurement
Dinh Thai Bao; Truong Cong Tuan; Tatsutoshi Shioda
Journal of Science and Technology: Smart Systems and Devices, Volume：32, Number：2, First page：39, Last page：46, May 2022, [Reviewed]
インライン全数検査を目指す光表面形状計測システム
塩田達俊
Volume：33, Number：1, First page：10, Last page：16, Jan. 2022, [Reviewed]
インライン検査用シングルショットOCTの開発
細田 真希; 太田 和哉; 志賀 代康; 塩田 達俊
Volume：32, Number：12, First page：8, Last page：11, Dec. 2021, [Reviewed]
インライン全数検査の実現へ向けた非接触光表面形状計測
塩田達俊
Volume：72, Number：8, First page：517, Last page：525, Aug. 2021, [Reviewed]
Rapid optical tomographic vibrometry using a swept multi-gigahertz comb Samuel Choi; Takeru Ota; Fumiaki Nin; Tatsutoshi Shioda; Takamasa Suzuki; Hiroshi Hibino
Optics Express,
Volume：29,
Number：11,
First page：16749,
Last page：16749, May 2021,
[Reviewed],
［International magazine］We propose a rapid tomographic vibrometer technique using an optical comb to measure internal vibrations, transient phenomena, and tomographic distributions in biological tissue and microelectromechanical system devices at high frequencies. This method allows phase-sensitive tomographic measurement in the depth direction at a multi-MHz scan rate using a frequency-modulated broadband electrooptic multi-GHz supercontinuum comb. The frequency spacing was swept instantaneously in time and axisymmetrically about the center wavelength via a dual-drive Mach-Zehnder modulator driven by a variable radio frequency signal. This unique sweeping method permits direct measurement of fringe-free interferometric amplitude and phase with arbitrarily changeable measurement range and scan rate. Therefore, a compressive measurement can be made in only the depth region where the vibration exists, reducing the number of measurement points. In a proof-of-principle experiment, the interferometric amplitude and phase were investigated for in-phase and quadrature phase-shifted interferograms obtained by a polarization demodulator. Tomographic transient displacement measurements were performed using a 0.12 mm thick glass film and piezo-electric transducer oscillating at 10-100 kHz with scan rates in the range 1-20 MHz. The depth resolution and precision of the vibrometer were estimated to be approximately 25 µm and 1.0 nm, respectively.
The Optical Society, English, Scientific journal
DOI：https://doi.org/10.1364/oe.425972DOI ID：10.1364/oe.425972,
eISSN：1094-4087,
PubMed ID：34154231 インライン全数検査を目指す非接触光表面形状計測システム
Volume：31, Number：3, First page：45, Last page：50, Mar. 2021, [Reviewed]
25.6a tbps pre-compensated waveform propagation using optical frequency comb synthesizer/analyzer
Nasrin Sultana; Hiroaki Tada; Hayate Imai; Tatsutoshi Shioda
Optics InfoBase Conference Papers, 2021, [Reviewed]
A scanless dispersion pre-compensation system for an ultrafast 25.6 waveform using multilevel 8-ary amplitude and 32-ary phase modulation was controlled and compensated by a 200 GHz optical frequency comb synthesizer with a 6.4 THz bandwidth.
The Optical Society, English, International conference proceedings
SCOPUS ID：85119449285
Dispersion pre-compensation of 25.6 Tbps waveforms using an optical frequency comb synthesizer/analyzer Nasrin Sultana; Hiroaki Tada; Hayate Imai; Tatsutoshi Shioda
Optics Communications,
Volume：475, Nov. 2020,
[Reviewed]© 2020 In this study, we propose and demonstrate a dispersion compensation system for an ultrafast 25.6 Tbps waveform using multilevel 8-ary amplitude and 32-ary phase modulation. The waveform bit period was 312.5 fs, which was controlled and compensated by a 200 GHz optical frequency comb (OFC) synthesizer with a 6.4 THz bandwidth. Dispersion spectra were measured in parallel and simultaneously (within 1 ms), based on single-shot dual-heterodyne mixing by introducing an OFC and arrayed waveguide grating to separate sidebands. An optical pulse synthesizer (OPS) can individually control the phase and amplitude spectra of the OFC. To control transmitted waveforms in a dispersed media, the OPS can be oppositely biased to feed the measured dispersion back into the source waveform when it generates an arbitrary waveform. In this study, a 25.6 Tbps dispersion-free waveform was successfully transmitted through a 10.55 km fiber.
Scientific journal
DOI：https://doi.org/10.1016/j.optcom.2020.126196Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85087200712&origin=inwardScopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=85087200712&origin=inwardDOI ID：10.1016/j.optcom.2020.126196,
ISSN：0030-4018,
SCOPUS ID：85087200712 2D Single-shot Optical Coherence Tomography under Vibration Environment Toshiki Awane; Tatsutoshi Shioda
2020 Conference on Lasers and Electro-Optics Pacific Rim, CLEO-PR 2020 - Proceedings, Aug. 2020,
[Reviewed]We demonstrated the performance of 2D single-shot tomography system for vibrating sample. The frequency dependence was investigated with the camera shutter speed of \\sim 1 \\mu \\mathrm{s}, which is faster than conventional OCT.
Institute of Electrical and Electronics Engineers Inc., English, International conference proceedings
DOI：https://doi.org/10.1364/CLEOPR.2020.C10F_4DOI ID：10.1364/CLEOPR.2020.C10F_4,
SCOPUS ID：85098093049 Dispersion spectroscopy with optical frequency comb-based single-shot dual-heterodyne mixing Sultana Nasrin; Hiroaki Tada; Leona Yuda; Tatsutoshi Shioda
Applied Optics,
Volume：58,
Number：33,
First page：9044,
Last page：9050, Nov. 2019,
[Reviewed]© 2019 Optical Society of America. We present a novel approach to high-speed dispersion spectroscopy that realizes a wide dynamic range, by simultaneous and parallel phase measurement using scanless dual-heterodyne mixing of 50 and 1.4 GHz frequency intervals. This system can realize parallel measurements of the relative phases between adjacent frequencies by introducing an optical frequency comb and intensity modulator to generate adjacent frequency and arrayed waveguide grating to separate the sidebands. The experimental results using single-mode fibers, whose lengths range from 0 to 92 km, indicated a 26 nm dispersion spectrum, 1785 ps/nm measurement range, and 0.27 ps/nm measurement uncertainty in 1 ms.
Scientific journal
DOI：https://doi.org/10.1364/AO.58.009044Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85075268809&origin=inwardScopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=85075268809&origin=inwardDOI ID：10.1364/AO.58.009044,
ISSN：1559-128X,
eISSN：2155-3165,
PubMed ID：31873579,
SCOPUS ID：85075268809 High-resolution spectroscopy using a frequency-variable comb light source Hiroaki Sugimoto; Mitsutaka Ito; Motohiro Koriba; Satoshi Seki; Tatsutoshi Shioda; Yosuke Tanaka; Ken Kashiwagi; Takashi Kurokawa
2016 IEEE Photonics Conference, IPC 2016,
First page：152,
Last page：153, Jan. 2017,
[Reviewed]© 2016 IEEE. We propose a high-resolution spectroscopy using 12.5-GHz-spaced laser frequency comb whose individual lines are shifted continuously using a single-sideband modulator. It was applied to measure the absorption spectrum of H13C14N gas in 1.55 μm wavelength range in MHz resolution.
IEEE, English, International conference proceedings
DOI：https://doi.org/10.1109/IPCon.2016.7831021Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85014248152&origin=inwardScopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=85014248152&origin=inwardDOI ID：10.1109/IPCon.2016.7831021,
ISSN：2374-0140,
SCOPUS ID：85014248152,
Web of Science ID：WOS:000406880100080 Optical dispersion spectroscopy using optical frequency comb applied to dual-heterodyne mixing Kaishu Kasuga; Takayuki Miyamoto; Tatsutoshi Shioda
Proceedings of SPIE - The International Society for Optical Engineering,
Volume：9754, 2016
© 2016 SPIE. The optical dispersion can be obtained from the adjacent relative phase between neighbor peaks in the optical frequency comb. Thus, the dispersion measurement becomes possible by measuring the relative phase spectrum. Our group has experimentally confirmed the operation principle by parallel capturing of the dispersion spectrum using an arrayed waveguide grating. We have proposed a dual-heterodyne mixing that obtained relative phases (ΔΦ) by fitting data of beat intensity versus optical path length difference. The path difference was applied by a delay line. In this study, we removed the delay line to realize a fast measurement by measuring simultaneous three relative phases with path length differences corresponding to π/2 or π, with which we have measured the dispersion in millisecond speed (250 sec. in previous). In general, it is effective to measured chromatic dispersion using high-speed signal transmission in the fundamental scientific research, such as the analysis of material properties and telecommunications. It is, however, that limit of cutoff frequency using measurement is the restriction on increasing of the speed. Our proposed method to observe it on a frequency domain is effective for the high-speed signal processing.
International conference proceedings
DOI：https://doi.org/10.1117/12.2212365Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84987643679&origin=inwardScopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=84987643679&origin=inwardDOI ID：10.1117/12.2212365,
ISSN：0277-786X,
eISSN：1996-756X,
SCOPUS ID：84987643679 A pseudo optical frequency comb interferometry by an optical resonator and a high-speed swept-source for 2D single-shot tomography and profilometry Q. T. Banh; T. Shioda
Proceedings of SPIE - The International Society for Optical Engineering,
Volume：9754, 2016
© 2016 SPIE. Pseudo optical frequency comb using a high-speed frequency laser scanner and an optical resonator is generated as a virtual broadband lightsource for the time-domain 2D single-shot tomography and profilometry. High-speed laser scanner (40 kHz) is realized using a broadband semiconductor optical amplifier (SOA) whose individual wavelengths are consequently picked up by a conventional grating setup and a high speed polygon mirror. The performance of the pseudo frequency comb is confirmed by a measurement of a reference step-height sample with an optical zooming operation.
International conference proceedings
DOI：https://doi.org/10.1117/12.2211995Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84987605258&origin=inwardScopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=84987605258&origin=inwardDOI ID：10.1117/12.2211995,
ISSN：0277-786X,
eISSN：1996-756X,
SCOPUS ID：84987605258 Spatially resolved spectroscopy using swept-source optical interferometry Ryoma Onita; Tatsutoshi Shioda
Proceedings of SPIE - The International Society for Optical Engineering,
Volume：9754, 2016
© 2016 SPIE. We describe principle of spatially-resolved spectroscopy using swept source optical interferometry and demonstrate it using a multi-layered polypropylene and glass plates piled sample. The advantages of this technique compared to conventional spectroscopy technique are realizing spatially-resolved spectroscopy as transmittance spectra of each layer and obtaining tomographic image of the sample simultaneously. Moreover, potential for spectroscopy is the method we propose can calculate absorption coefficient of each mediums. In this demonstration, we could 1D tomographic image of multi-layered sample and characterize PP layer and glass layer by comparing transmittance spectra in near infrared region.
International conference proceedings
DOI：https://doi.org/10.1117/12.2212228Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84987618893&origin=inwardScopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=84987618893&origin=inwardDOI ID：10.1117/12.2212228,
ISSN：0277-786X,
eISSN：1996-756X,
SCOPUS ID：84987618893 Frequency-domain single-shot optical frequency comb tomography using VIPA Takumi Miyaoka; Tatsutoshi Shioda
Proceedings of SPIE - The International Society for Optical Engineering,
Volume：9754, 2016
© 2016 SPIE. Novel two-dimensional single-shot imaging optical system based on Frequency-domain interferometry using a virtually imaged phased array is proposed. The VIPA simultaneously outputs incoherent optical frequency combs (OFCs) whose teeth interval are scanned as a function of its output angle. Teeth intervals of the OFCs only in a reference are spatially swept by using of a VIPA whose advantage compared to an optical resonator. Thus, the single-shot imaging system can be realized with the FSR scanned frequency-domain OFC interference monitored by CCD. This system enable high speed 2-dimensional tomographic image without mechanical moving part. And the axial measurement range is not limited by using multi-order interference that is generated by OFCs interferometry. We will present the operation principle with its confirmed results in terms of both simulation and experiment.
International conference proceedings
DOI：https://doi.org/10.1117/12.2212093Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84987653325&origin=inwardScopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=84987653325&origin=inwardDOI ID：10.1117/12.2212093,
ISSN：0277-786X,
eISSN：1996-756X,
SCOPUS ID：84987653325 Two-dimensional high-speed and long-range tomography and profilometry using liquid-crystal Fabry-Perot resonator Tuan Quoc Banh; Kohei Suzuki; Munehiro Kimura; Tatsutoshi Shioda
Applied Optics,
Volume：54,
Number：4,
First page：912,
Last page：918, 2015,
[Reviewed]© 2015 Optical Society of America. A two-dimensional high-speed, long-range tomography and profilometry based on a low-coherence optical interferometry has been developed. A liquid-crystal Fabry-Perot resonator is fabricated to be a lowcoherence optical frequency comb generator for expanding the measurement depth of the tomography and profilometry. The line-shape interference fringes with the individual fringe orders are obtained by a CCD camera in real time. The relative optical length, corresponding to the sample depth information, can be derived from the positions of the interference fringes on the CCD camera and their corresponding fringe orders. The fringe orders can be rapidly calculated using the effectiveness of the changeable extraordinary refractive index of the liquid-crystal material of the resonator. The finesse of the liquid-crystal resonator is approximate 9, giving an expansion of the measurement range of up to 9-fold (∼8 mmdepth)with a resolution of profilometry and tomography of 3.7 μmand11μm, respectively.
Scientific journal
DOI：https://doi.org/10.1364/AO.54.000912Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84942372468&origin=inwardScopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=84942372468&origin=inwardDOI ID：10.1364/AO.54.000912,
ISSN：1559-128X,
eISSN：2155-3165,
SCOPUS ID：84942372468 Single-shot, long-range, and zoomable optical tomography and profilometry using a diffraction grating and a CCD camera Q. T. Banh; T. Kosakai; T. Shioda
Proceedings of SPIE - The International Society for Optical Engineering,
Volume：9655, 2015
© 2015 Copyright SPIE. We have developed a novel single-shot optical tomography and profilometry that is able to measure the tomograms and surface profiles of a sample in realtime with long measurable range. The system comprises of an optical frequency comb interferometry and a diffraction grating. The grating plays as a spatial phase modulator (SPM), so that the realtime interference images can be achieved by a CCD camera. Owing to the diffraction lights by the SPM, the axial zooming operation of the proposed system can be realized. The zooming range of the proposed system depends on how many diffraction orders are generated by the SPM. Measurements of a reference Gauge-block step-height sample at different diffraction orders are performed to evaluate the proposed system.
International conference proceedings
DOI：https://doi.org/10.1117/12.2184422Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84939214012&origin=inwardScopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=84939214012&origin=inwardDOI ID：10.1117/12.2184422,
ISSN：0277-786X,
eISSN：1996-756X,
SCOPUS ID：84939214012 Novel two-dimensional single-shot optical imaging system by VIPA-comb interferometry Takumi Miyaoka; Tatsutoshi Shioda
Proceedings of SPIE - The International Society for Optical Engineering,
Volume：9655, 2015
© 2015 Copyright SPIE. We propose a novel system for a two-dimensional (2-D) single-shot tomography and profilometry that can be realized by installing a Virtually Imaged Phased Array (VIPA) into a 2-D interferometer with a CCD. The VIPA simultaneously outputs incoherent optical frequency combs (OFC) whose teeth interval, such as free-spectral range (FSR), are scanned as a function of its output angle when the low-coherent light source is incident into the VIPA. Thus, the single-shot imaging can be realized with the FSR scanned Fourier-domain OFC interference monitored by the CCD. In other words, the fast imaging without mechanical moving part can be operated by the proposed OFC interferometry. And VIPA can use all of incident light. So this system enables to realize a high energy efficient interference measurement. FSR of the output light of the VIPA is nonlinear with respect to the sweep direction. So we simulated the characteristics of the VIPA. As a result, we knew linearity optimal output angle depend on reflective index of the VIPA. And the VIPA can change the measurement range on the CCD by the number. In other word, the VIPA can zoom in and out no mechanical part. We will present the operation principle with its confirmed results in terms of both simulation and experiment.
International conference proceedings
DOI：https://doi.org/10.1117/12.2185168Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84939168602&origin=inwardScopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=84939168602&origin=inwardDOI ID：10.1117/12.2185168,
ISSN：0277-786X,
eISSN：1996-756X,
SCOPUS ID：84939168602 Magneto-optical diffraction by periodic lateral arrays composed of GMR structures of Pt/Co free layers having perpendicular magnetization Kakeru Wada; Tsukasa Kobayashi; Akira Emoto; Ken Ichi Aoshima; Kenji Machida; Kiyoshi Kuga; Tatsutoshi Shioda; Hiroshi Ono; Hiroshi Kikuchi; Naoki Shimidzu; Takayuki Ishibashi
Optics Communications,
Volume：323,
First page：123,
Last page：127, Jul. 2014,
[Reviewed]A first-order beam diffracted by periodic arrays of GMR structures consisting of Pt/Co free layers having perpendicular magnetization without a top electrode is investigated. Linear and two-dimensional arrays of various shapes having sizes of 10-50 μm and periods of 20-100 μm embedded in SiO 2 are fabricated. The angles of the plane of polarization for first or (1,0) diffraction spots at a wavelength of 633 nm are measured to be approximately 0.5 for all samples. The polarization angles for one- and two-dimensional arrays of magnetic patterns are studied theoretically by assuming that the structures have sinusoidal magnetic distributions. They are found to depend on the Kerr rotation angle of the Pt/Co multilayer and on the difference in reflectance between the Pt/Co and SiO2, but they are independent of the periodicities, sizes, and shapes of the patterns. On the other hand, the diffraction efficiencies due to the magneto-optical effect depend on the reflectance and Kerr rotation angles of the magnetic materials. The diffraction efficiency of the component arising from the magneto-optical effect is discussed. © 2014 Elsevier B.V.
Scientific journal
DOI：https://doi.org/10.1016/j.optcom.2014.02.064Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84897857352&origin=inwardScopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=84897857352&origin=inwardDOI ID：10.1016/j.optcom.2014.02.064,
ISSN：0030-4018,
SCOPUS ID：84897857352 FDTD simulation for polarization state of scattered light in apertureless SNOM Y. Cai; Q. Meng; A. Emoto; T. Shioda; H. Ono; T. Ishibashi
J. Mag. Soci. Jpn.,
Volume：38,
Number：3-2,
First page：127,
Last page：130, Apr. 2014,
[Reviewed]Polarization properties in aperture-less scanning near-field optical microscopy (SNOM) were investigated using the 3D finite-difference time-domain (FDTD) method. We found that scattered light became elliptically polarized with linear or circular-polarized light illumination, and the polarization state of scattered light was preserved. In addition, Jones matrices that express the relationship between incident light and scattered light in terms of the polarization states were successfully obtained. We succeeded in calculating the polarization state of scattered light with arbitrary polarized light illumination by using the Jones matrix method.
日本磁気学会, English, International conference proceedings
DOI：https://doi.org/10.3379/msjmag.1403R004DOI ID：10.3379/msjmag.1403R004,
ISSN：1882-2924,
CiNii Articles ID：130003394340,
CiNii Books ID：AA12297999 Application of dual-heterodyne mixing to optical phase-shift keying Toshiaki Yamazaki; Tatsutoshi Shioda
Japanese Journal of Applied Physics,
Volume：53,
Number：1, Jan. 2014,
[Reviewed]Dual-heterodyne mixing has been developed to detect high-speed optical signal waveforms and measure not only the amplitude spectrum but also the phase spectrum. In the present study, this method was applied to a simple experiment that demodulated intensity-modulated terabit signals, and it successfully demodulated an 80 ps non monotonic optical pulse train of 12.5 Gbps 8 bit phase-modulated signals as arbitrary waveforms with dual-heterodyne mixing. These results will be the foundation for phase-shift-keying technology that increases future communication capacity.© 2014 The Japan Society of Applied Physics.
IOP PUBLISHING LTD, English, Scientific journal
DOI：https://doi.org/10.7567/JJAP.53.012501Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84892401428&origin=inwardScopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=84892401428&origin=inwardDOI ID：10.7567/JJAP.53.012501,
ISSN：0021-4922,
eISSN：1347-4065,
SCOPUS ID：84892401428,
Web of Science ID：WOS:000331412300025 Development of an incoherent optical frequency comb interferometer for long-range and scanless profilometry and tomography Tuan Quoc Banh; Kohei Suzuki; Tatsutoshi Shioda
Optics Communications,
Volume：296,
First page：1,
Last page：8, Jun. 2013,
[Reviewed]An optical resonator was installed as an incoherent frequency comb generator into a two-dimensional single-shot profilometry and tomography system to increase the measurement range up to 30 times compared with a conventional white-light interferometer. The dynamic range of the sample set position was experimentally confirmed to be ∼28 mm, equivalent to the coherency of the resonator. Scanless measurement can be achieved through high-order comb interference. In this study, we demonstrated tomography with a resolution of ∼11 μm and effective high-order interference fringe discrimination. © 2013 Elsevier B.V. All rights reserved.
Scientific journal
DOI：https://doi.org/10.1016/j.optcom.2013.01.027Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84875886867&origin=inwardScopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=84875886867&origin=inwardDOI ID：10.1016/j.optcom.2013.01.027,
ISSN：0030-4018,
SCOPUS ID：84875886867 Polarization state of scattered light in apertureless reflection-mode scanning near-field optical microscopy Yongfu Cai; Mitsuharu Aoyagi; Akira Emoto; Tatsutoshi Shioda; Takayuki Ishibashi
Journal of Magnetics,
Volume：18,
Number：3,
First page：317,
Last page：320, 2013,
[Reviewed]We studied the polarization state in an apertureless scanning near-field microscopy (a-SNOM) operating in reflection mode by using three-dimensional Finite-difference Time-domain (FDTD) method. As a result, the electric field around tip apex in the near-field region enhanced four times stronger than the incident light for ppolarization when the tip-sample separation was 10 nm. We find that the p- and s-polarization state is maintained for the scattered light when the probe is perpendicular to the sample. When the probe is not perpendicular to the sample, the polarization state of scattered light will rotate an angle that equals to the inclination angle of probe with p-polarization illumination. On the other hand, the polarization state will not rotate with s-polarization illumination. © The Korean Magnetics Society. All rights reserved.
Scientific journal
DOI：https://doi.org/10.4283/JMAG.2013.18.3.317Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84884804066&origin=inwardScopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=84884804066&origin=inwardDOI ID：10.4283/JMAG.2013.18.3.317,
ISSN：1226-1750,
SCOPUS ID：84884804066 Multi-gigahertz frequency comb-based interferometry using frequency-variable supercontinuum generated by optical pulse synthesizer Samuel Choi; Ken Kasiwagi; Yosuke Kasuya; Shuto Kojima; Tatsutoshi Shioda; Takashi Kurokawa
Optics Express,
Volume：20,
Number：25,
First page：27820,
Last page：27829, Dec. 2012,
[Reviewed]A multi-gigahertz frequency comb (MGFC)-based interferometer was developed for profilometry and tomography using a frequency variable supercontinuum (SC). The comparatively flattened and broadened SC light source with variable multi-gigahertz interval frequency was developed using an optical pulse synthesizer and highly nonlinear dispersion flattened fiber. The generated SC provided a stable interference output with a full width half maximum of 19 μ m during interval frequency sweeping of over 400 MHz. We experimentally confirmed that the interference signal exhibited an envelope-only waveform without fringes, which enabled the drastic reduction of the sampling points resulting in high speed measurement. A full-field 3-D image with 320 × 256 × 300 pixels was acquired with a measurement time of only 10 seconds. It was demonstrated that the MGFC-based interferometer with the novel SC light source has the potential for application in a high speed full-field 3-D metrology. © 2012 Optical Society of America.
Scientific journal
DOI：https://doi.org/10.1364/OE.20.027820Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84870584945&origin=inwardScopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=84870584945&origin=inwardDOI ID：10.1364/OE.20.027820,
eISSN：1094-4087,
PubMed ID：23262727,
SCOPUS ID：84870584945 Three-wavelength parallel optical fiber dispersion measurement using dual-heterodyne mixing Tatsutoshi Shioda; Naoya Shimizu; Masaichi Nakamura
Applied Optics,
Volume：51,
Number：27,
First page：6586,
Last page：6593, Sep. 2012,
[Reviewed]We propose a novel optical dispersion measurement system using dual-heterodyne mixing to measure the relative phase. The system can realize parallel measurement of the relative phases between adjacent frequencies by introducing optical modulators to generate optical sidebands from a laser light source and an arrayed waveguide grating to separate the sidebands. To realize a wide dispersion range, different frequency intervals for the adjacent frequencies were combined in the system. One is the three-frequency optical dispersion measurement system (three-frequency measurement), which has been developed to measure the relative phase between adjacent peaks of an optical frequency spectrum with intervals of 25 GHz generated without any frequency scanning. The other is the four-frequency optical dispersion measurement system (four-frequency measurement) with intervals of 2 GHz generated from the threefrequency sets to expand the measurement range. The experimental results using single-mode optical fibers of different lengths from 0 to 90 km indicated the dispersion slope to be 16.8 ps/nm/km with a measurement range of 2500 ps/nm and an uncertainty of less than 1 ps/nm. The proposed system provides advantages to enable parallel measurement on a frequency axis without a high-speed (GHz) photodetector, even though GHz spacing on the optical scale is used, thus reflecting the dual-heterodyne mixing. © 2012 Optical Society of America.
Scientific journal
DOI：https://doi.org/10.1364/AO.51.006586Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84866640666&origin=inwardScopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=84866640666&origin=inwardDOI ID：10.1364/AO.51.006586,
ISSN：1559-128X,
eISSN：1539-4522,
SCOPUS ID：84866640666 Ultrafast optical frequency comb synthesizer and analyzer Tatsutoshi Shioda; Toshiaki Yamazaki
Optics Letters,
Volume：37,
Number：17,
First page：3642,
Last page：3644, Sep. 2012,
[Reviewed]We propose an ultrafast optical arbitrary waveform synthesizing/analyzing technique demonstrated with 2 Tbit/s waveforms. An ultrafast waveform was generated by manipulating the amplitude and phase of a 400 GHz optical frequency comb using a newly developed colorless optical synthesizer. The 400 GHz optical frequency comb was generated from a 25 GHz optical frequency comb using a colorless arrayed waveguide grating. This waveform was then analyzed on the frequency axis using a custom heterodyne-detection technique based on the dual-heterodyne mixing method. The phase and amplitude spectra can be observed in parallel using another optical frequency comb as a reference combined with an arrayed waveguide grating. This optical system, named the ultrafast optical frequency comb synthesizer and analyzer, can synthesize and analyze an arbitrary waveform in the THz frequency region. © 2012 Optical Society of America.
Scientific journal
DOI：https://doi.org/10.1364/OL.37.003642Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84865794830&origin=inwardScopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=84865794830&origin=inwardDOI ID：10.1364/OL.37.003642,
ISSN：0146-9592,
eISSN：1539-4794,
SCOPUS ID：84865794830 Two-dimensional single-shot tomography using a virtually imaged phased array and a spatial phase modulator Tatsutoshi Shioda; Takashi Morisaki; Tuan Quoc Banh; Kohei Suzuki
Applied Optics,
Volume：51,
Number：21,
First page：5224,
Last page：5230, Jul. 2012,
[Reviewed]A virtually imaged phased array (VIPA) installed optical interferometer has been expanded to the two-dimensional (2D) tomography from the previous one-dimensional single-shot imaging technique with keeping the resolution and the measurement range. A single-shot measurement has been realized by a spatial phase modulator installed in the optical interferometer and tracing the delay time to pixel numbers on a 2D charge-coupled device (CCD) image sensor. The flexibility of the sample position was experimentally confirmed to be >25 mm, in relation to the VIPA coherency, for which the number of the interference order was confirmed to be 35. As a demonstration, a surface profile of stacked gauge blocks was observed. The repeatability of the surface position was 5 μm for the surface profilometry. In addition, a multilayer structure was observed using a glass plate. The experimental resolution was 53 μm when the amplified spontaneous emission light generated by the optical fiber amplifier was used for the light source. The single-shot measurement was confirmed by the 2D-CCD at a frame rate of 30 frames per second (FPS), and it provided evidence that the 2D scanless profilometry was successfully achieved using the VIPA optical device. © 2012 Optical Society of America.
Scientific journal
DOI：https://doi.org/10.1364/AO.51.005224Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84864194032&origin=inwardScopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=84864194032&origin=inwardDOI ID：10.1364/AO.51.005224,
ISSN：1559-128X,
eISSN：1539-4522,
SCOPUS ID：84864194032 Spectral waveform measurement of 2 THz optical frequency comb by dual-heterodyne mixing Toshiaki Yamazaki; Mitsuru Kuzuwata; Tatsutoshi Shioda
Journal of the Optical Society of America B: Optical Physics,
Volume：29,
Number：7,
First page：1707,
Last page：1711, Jul. 2012,
[Reviewed]A technique for measuring the relative phase between optical longitudinal modes in an optical frequency comb (OFC) has been proposed, and applied to the characterization of the OFC. The measurement frequency range was expanded to 2 THz using the OFC of a line spacing of 10 GHz. Furthermore, an algorithm for data analysis was proposed by calculating Fourier transformation of the fragmentized waveform of the data measured by the dualheterodyne mixing method. As a result, a pulse width of 2.1 ps was observed on a time scale of 100 ps with a resolution of 500 fs, which is inversely proportional to the measured frequency band in general (2 THz in this study). These results were also compared with those obtained from an optical autocorrelator. The measured electric field spectra provide a lot of information, involving a frequency-resolved optical gating (FROG) trace and a phase variation profile plotted against time. Amplitude and phase spectral evolutions were reconstructed directly from the electric field spectra and referred to as a dual-heterodyne mixing trace. In conclusion, it was confirmed that the proposed technique is effective in reading out detailed information from the ultrafast waveform measurement. © 2012 Optical Society of America.
Scientific journal
DOI：https://doi.org/10.1364/JOSAB.29.001707Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84863827992&origin=inwardScopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=84863827992&origin=inwardDOI ID：10.1364/JOSAB.29.001707,
ISSN：0740-3224,
SCOPUS ID：84863827992 High-resolution spectroscopy using interleaved 100 GHz optical frequency comb scanned by phase modulator Tatsutoshi Shioda; Kenichiro Fujii; Ken Kashiwagi; Takashi Kurokawa
Optics Communications,
Volume：284,
Number：21,
First page：5180,
Last page：5184, Oct. 2011,
[Reviewed]A high-resolution spectroscopy technique is proposed with an optical phase modulator combined with an interleaved optical frequency comb. The optical phase modulator and a frequency-locked laser light guarantee a spectral resolution less than 1 MHz on an absolute frequency axis. A wide measurement frequency range was realized using a 25 GHz optical frequency comb lying over a 4 THz frequency region. An extraction of single tooth intensity from the comb was realized by a heterodyne technique with a frequency-tunable laser used as a local oscillator. Also, the 25 GHz optical frequency comb was interleaved to generate four 100-GHz combs for removing the crosstalk from the 25 GHz neighboring sidebands in the teeth. This proposed spectroscopy technique was experimentally demonstrated with a resonator of less than 1 MHz linewidth and a H13C14N gas cell. Thus, a measurement frequency range higher than 4 THz (1530 nm-1560 nm) was confirmed with an effective spectral resolution 100 kHz order. In addition, the characteristics of the proposed system were compared with those of the previous system with a single-sideband (SSB) optical modulator. © 2011 Elsevier B.V. All rights reserved.
ELSEVIER SCIENCE BV, English, Scientific journal
DOI：https://doi.org/10.1016/j.optcom.2011.07.006Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=80052816683&origin=inwardScopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=80052816683&origin=inwardDOI ID：10.1016/j.optcom.2011.07.006,
ISSN：0030-4018,
eISSN：1873-0310,
SCOPUS ID：80052816683,
Web of Science ID：WOS:000295608600027 Vector gratings fabricated by polarizer rotation exposure to hydrogen-bonded liquid crystalline polymers Akira Emoto; Takumi Wada; Tatsutoshi Shioda; Tomoyuki Sasaki; Sayaka Manabe; Nobuhiro Kawatsuki; Hiroshi Ono
Japanese Journal of Applied Physics,
Volume：50,
Number：3, Mar. 2011,
[Reviewed]We present a simple yet efficient, competitive, and practical fabrication method, called "polarizer rotation exposure", for preparing vector gratings with a large area and a high diffraction efficiency. The polarization states of ultraviolet light were modulated by rotating the polarizer, and the resultant ultraviolet light was line-focused onto hydrogen-bonded liquid crystalline polymer films set on a linear stage. Mesogenic molecules in the polymer films were reoriented according to the light electric vectors, and vector gratings in which the optical anisotropy is periodically modulated were fabricated by the polarizer rotation exposure method. © 2011 The Japan Society of Applied Physics.
Scientific journal
DOI：https://doi.org/10.1143/JJAP.50.032502Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=79953081260&origin=inwardScopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=79953081260&origin=inwardDOI ID：10.1143/JJAP.50.032502,
ISSN：0021-4922,
eISSN：1347-4065,
SCOPUS ID：79953081260 Single-shot tomography by means of VIPA and spatial phase modulator installed optical interferometer Tatsutoshi Shioda; Takashi Morisaki; Hiroshi Ono
Optics Communications,
Volume：284,
Number：1,
First page：144,
Last page：147, Jan. 2011,
[Reviewed]A VIPA (virtually imaged phased array) installed optical interferometer has been proposed for scanless tomography. Also, a spatial phase modulator and a line-image sensor were installed into the interferometer to realize single-shot measurement by displaying the delay time on a line-image sensor. The correlation peak function was observed on the line-sensor at same time. The envelope of the peak was given by the inverse Fourier transformation of the light source spectrum. The peak position on the image-sensor reflects the sample structure. Furthermore, the correlation peaks are appeared repeatedly along the delay time of the interferometer. The repeated correlation function raise an alignment flexibility of the sample set position, which has been limited in the traditional time-domain interferometry involving the delay time to be zero. The flexibility was experimentally confirmed at 25 mm related to the VIPA coherency. The resolution was experimentally 52.5 μm when the ASE (amplified spontaneous emission) light source of the optical fiber amplifier was used. The single-shot measurement was realized by a line-image sensor of the 30 frames per second. The repeatability of the interfered peak position was 5 μm by the tunable mirror position. The one-dimensional scanless measurement was demonstrated by use of 3-layer glass plates. © 2010 Elsevier B.V. All rights reserved.
ELSEVIER SCIENCE BV, English, Scientific journal
DOI：https://doi.org/10.1016/j.optcom.2010.09.028Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=78649683674&origin=inwardScopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=78649683674&origin=inwardDOI ID：10.1016/j.optcom.2010.09.028,
ISSN：0030-4018,
SCOPUS ID：78649683674,
Web of Science ID：WOS:000285893200023 Chronological investigations of Raman-Nath diffraction grating inscribed by direct laser writing in photoreactive monomer base mixtures Akira Emoto; Suzana Binti Baharim; Tomoyuki Sasaki; Tatsutoshi Shioda; Akifumi Ogiwara; Hiroshi Ono
Japanese Journal of Applied Physics,
Volume：49,
Number：12, Dec. 2010,
[Reviewed]Phase-type diffraction gratings, inscribed using an ultraviolet laser beam, were grown in a thin film of a photoreactive monomer base mixture over a period of several hours. The photopolymerization of monomers and subsequent molecular migrations generated both surface relief gratings and inner refractive index modulation. The changes in the diffraction intensity over time revealed the pronounced behavior of grating formation, which can be explained using a time-dependent model based on the Raman-Nath diffraction theory. Homogeneous irradiation with ultraviolet light during the growth enabled us to fix the diffraction characteristics of the gratings at an arbitrary moment in time, allowing us to tailor the resultant diffraction gratings according to a desired specification. This sequential process can have practical applications. © 2010 The Japan Society of Applied Physics.
Scientific journal
DOI：https://doi.org/10.1143/JJAP.49.122502Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=79551663439&origin=inwardScopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=79551663439&origin=inwardDOI ID：10.1143/JJAP.49.122502,
ISSN：0021-4922,
eISSN：1347-4065,
SCOPUS ID：79551663439 Proposal of dual-heterodyne-mixing method and application to high-speed waveform measurement using low-speed equipments Tatsutoshi Shioda; Toshiaki Yamazaki
Optics Communications,
Volume：283,
Number：23,
First page：4733,
Last page：4740, Dec. 2010,
[Reviewed]A novel method to measure a relative phase between frequency-different optical wavelengths has been proposed and named as Dual-heterodyne-mixing method. The operation principle of the method is represented, where the relative phase is simply described as dc voltage. The operation principle was experimentally confirmed with 0- and π-phase-different optical pairs generated by an intensity modulator. Also, it has been applied for a high-speed signal sensing with a high-resolution amplitude spectrum measurement method. A 12.5 Gbps signal sensing with 1/63 relatively low-speed photodetector (200 MHz) was demonstrated. © 2010 Elsevier B.V. All rights reserved.
ELSEVIER SCIENCE BV, English, Scientific journal
DOI：https://doi.org/10.1016/j.optcom.2010.08.018Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=77957749952&origin=inwardScopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=77957749952&origin=inwardDOI ID：10.1016/j.optcom.2010.08.018,
ISSN：0030-4018,
SCOPUS ID：77957749952,
Web of Science ID：WOS:000283704800030 Photoinduced reorientation and polarization holography in photo-cross-linkable liquid crystalline polymer films with large birefringence Nobuhiro Kawatsuki; Ayumi Yamashita; Mizuho Kondo; Taro Matsumoto; Tatsutoshi Shioda; Akira Emoto; Hiroshi Ono
Polymer,
Volume：51,
Number：13,
First page：2849,
Last page：2856, Jun. 2010,
[Reviewed]A new photo-cross-linkable liquid crystalline polymer (PLCP) comprised 4-methoxycinnamoyloxy groups connected with a bistolane side group was synthesized to investigate thermally enhanced photoinduced molecular reorientation of a thin film with linearly polarized (LP) 365. nm light exposure. Due to the axis-selective photoreaction of the cinnamate groups followed by the thermally induced self-organization, large molecular reorientation parallel to the polarization of LPUV light (S>0.6) and large birefringence at the non-resonance region (Δ n=0.34 at 632.8. nm) were obtained. The obtained Δ n value is the largest among transparent PLCPs in the visible region. The influence of the degree of photoreaction and the annealing temperature on the thermally enhanced molecular reorientation behavior was explored in detail. Finally, for an application of thin optical devices using the PLCP films, pure polarization holographic gratings with large birefringence, which showed periodic molecularly oriented structure, were fabricated using a 325. nm He-Cd laser in various polarization modes and characterized their optical properties. © 2010 Elsevier Ltd.
Scientific journal
DOI：https://doi.org/10.1016/j.polymer.2010.04.043Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=77954817210&origin=inwardScopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=77954817210&origin=inwardDOI ID：10.1016/j.polymer.2010.04.043,
ISSN：0032-3861,
SCOPUS ID：77954817210 Magneto-optical imaging and coercivity mapping of GdFe spin-valve structures Takayuki Ishibashi; Terumasa Kosaka; Masayuki Naganuma; Tatsutoshi Shioda; Ken Ichi Aoshima; Nobuhiko Funabashi; Kenji MacHida; Kiyoshi Kuga; Naoki Shimidzu
Journal of Applied Physics,
Volume：107,
Number：9, May 2010,
[Reviewed]GdFe spin-valve structures, Si/bottom electrode/TbFeCo/CoFe (1 nm)/Cu (6 nm)/GdFe (10 nm)/Ru, with dimensions of 20×20 μ m2 were investigated by a magneto-optical imaging technique. In a parallel configuration, i.e., a configuration in which the magnetization directions of GdFe and TbFeCo layers are parallel, the coercivity (Hc) decreases when nucleation centers are present in the patterns. In the antiparallel configuration, although few nucleation centers are present the deviation in Hc is greater than that in the parallel configuration. © 2010 American Institute of Physics.
International conference proceedings
DOI：https://doi.org/10.1063/1.3367980Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=77951689530&origin=inwardScopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=77951689530&origin=inwardDOI ID：10.1063/1.3367980,
ISSN：0021-8979,
SCOPUS ID：77951689530 High-resolution spectroscopy based on optical phase modulator and optical frequency comb Tatsutoshi Shioda; Takayoshi Mori; Tatsuya Sugimoto; Yosuke Tanaka; Takashi Kurokawa
Optics Communications,
Volume：282,
Number：14,
First page：2909,
Last page：2912, Jul. 2009,
[Reviewed]A phase modulation of an optical frequency comb has been applied to measure a fine spectrum in the 1.5 μm wavelength range by the optical heterodyne-detection method. The measurement frequency range covered 25 GHz, which satisfies the frequency interval of the optical frequency comb, with a spectral resolution of 1 MHz. © 2009 Elsevier B.V. All rights reserved.
English, Scientific journal
DOI：https://doi.org/10.1016/j.optcom.2009.03.065Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=66249089171&origin=inwardScopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=66249089171&origin=inwardDOI ID：10.1016/j.optcom.2009.03.065,
ISSN：0030-4018,
CiNii Articles ID：80020411507,
SCOPUS ID：66249089171 Elastic continuum analysis and diffraction properties of two-dimensional liquid crystalline grating cells Hiroshi Ono; Masakata Hishida; Akira Emoto; Tatsutoshi Shioda; Nobuhiro Kawatsuki
Journal of the Optical Society of America B: Optical Physics,
Volume：26,
Number：6,
First page：1151,
Last page：1156, Jun. 2009,
[Reviewed]A detailed analysis of two-dimensional liquid crystalline grating cells is presented. Crossed liquid crystalline gratings were prepared using two kinds of photo-alignment polymers, i.e., poly(vinyl cinnamate) (PVCi) and photocrosslinkable polymer liquid crystal (PCLC). The effects of the anchoring strength of photo-alignment polymer films and crossing angles of grating vectors on one pair of photo-alignment substrates were extensively investigated using elastic continuum analysis, Jones calculus, and diffraction theory. The anchoring strength of our PCLC film was sufficiently strong, and experimental observation was in good agreement with the theoretical values obtained assuming the strong anchoring (fixed boundary conditions), although PCLC still has limits with the capability of photo-alignment of the low-molar-mass liquid crystals. ©2009 Optical Society of America.
Scientific journal
DOI：https://doi.org/10.1364/JOSAB.26.001151Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=67650751412&origin=inwardScopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=67650751412&origin=inwardDOI ID：10.1364/JOSAB.26.001151,
ISSN：0740-3224,
SCOPUS ID：67650751412 Power line monitoring system using fiber optic power supply Yosuke Tanaka; Tatsutoshi Shioda; Takashi Kurokawa; Junji Oka; Kazuyuki Ueta; Toshiharu Fukuoka
Optical Review,
Volume：16,
Number：3,
First page：257,
Last page：261, May 2009,
[Reviewed]We propose a novel power-line-monitoring system using optical fibers for transmitting power as well as signal. The principle is experimentally confirmed with a system composed of a monitoring side with a 1.5-μm laser diode, transmission line of a single mode fiber, and a sensing side having an efficient photovoltaic (PV) cell, electrical junction sensor, and low power liquid crystal optical modulator (LCOM). The PV cell generates the electrical power in the sensing side with a conversion efficiency of 20%. The LCOM is driven with low power of less than 50 μW, modulates the laser light with a signal indicating the power line condition, and transmits the optical signal. The developed sensing unit produces an optical signal having an extinction ratio of 15 dB with low optical power of 1.8 mW. Five systems were in operation for two years, faithfully monitoring the oil pressure in electrical cables every 20 min without incident. © 2009 The Optical Society of Japan.
English, Scientific journal
DOI：https://doi.org/10.1007/s10043-009-0048-xScopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=67149103682&origin=inwardScopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=67149103682&origin=inwardDOI ID：10.1007/s10043-009-0048-x,
ISSN：1340-6000,
eISSN：1349-9432,
CiNii Articles ID：10025304540,
SCOPUS ID：67149103682 Effects of phase shift between two photo-alignment substrates on diffraction properties in liquid crystalline grating cells Hiroshi Ono; Takeshi Shinmachi; Akira Emoto; Tatsutoshi Shioda; Nobuhiro Kawatsuki
Applied Optics,
Volume：48,
Number：2,
First page：309,
Last page：315, Jan. 2009,
[Reviewed]Diffractive optical devices using low-molar-mass liquid crystals are of great important for realizing numerical optical functions such as optical memory and information systems. In the present study the liquid crystalline gratings have been fabricated using a pair of photo-alignment substrates, and effects of the phase shift between the two photo-alignment substrates on the diffraction properties have been investigated. The liquid crystalline grating has been constructed with variable polarization dependence that can be controlled by the phase shift between the two photo-alignment substrates and twisted angles of the nematic directors. The theoretical considerations were also performed using the elastic continuum theory, Jones calculus, and diffraction theory. A guiding principle that controls the diffraction properties of the liquid crystalline grating cell was successfully presented. © 2009 Optical Society of America.
Scientific journal
DOI：https://doi.org/10.1364/AO.48.000309Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=60849109235&origin=inwardScopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=60849109235&origin=inwardDOI ID：10.1364/AO.48.000309,
ISSN：1559-128X,
eISSN：1539-4522,
SCOPUS ID：60849109235 Transmission and reflection phase gratings formed in azo-dye-doped chiral nematic liquid crystals Tomoyuki Sasaki; Akira Emoto; Tatsutoshi Shioda; Hiroshi Ono
Applied Physics Letters,
Volume：94,
Number：2, 2009,
[Reviewed]Transmission and reflection gratings were simultaneously formed in azo-dye-doped chiral nematic liquid crystals (N* LCs) with planar alignment. The formation process is based on a phototuning of the Bragg reflection band of the N* LC. The helical pitch of the photoreactive N* LC was spatially controlled with intensity variation of interference light. The resultant periodic structure showed both transmissive and reflective diffractions due to the spatially modulated light intensities. The observed dependence of diffraction efficiencies on the polarization states of the probe beam was well explained by considering a spatial modulation of the helical pitch. © 2009 American Institute of Physics.
Scientific journal
DOI：https://doi.org/10.1063/1.3072363Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=58349086208&origin=inwardScopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=58349086208&origin=inwardDOI ID：10.1063/1.3072363,
ISSN：0003-6951,
SCOPUS ID：58349086208 One- and two-dimensional anisotropic diffractive gratings formed by periodic orthogonal molecular alignment in a hydrogen-bonded liquid crystalline polymer Akira Emoto; Sayaka Manabe; Tatsutoshi Shioda; Hiroshi Ono; Nobuhiro Kawatsuki
Journal of Applied Physics,
Volume：105,
Number：10, 2009,
[Reviewed]Anisotropic diffractive gratings having periodic orthogonal molecular alignments are formed by a linearly polarized ultraviolet (LPUV) exposure through a photomask in hydrogen (H)-bonding liquid crystalline polymers (H-LCPs) using a unique molecular reorientation behavior. H-bonded side-chain groups of H-LCPs play an important role in the molecular reorientation and the resultant optical anisotropy originating from an intermolecular network composition. To evaluate its potential for optical applications, one- and two-dimensional diffractive gratings were fabricated and analyzed by both polarization optical microscopy and diffraction characteristics. As a result, anisotropic gratings using H-LCP were obtained with a high diffraction efficiency that was 80% of the theoretical maximum efficiency (33.9%) of thin diffractive gratings. Results of experimental and theoretical investigation reveal that the resultant molecular direction and optical anisotropy are generated and controlled by LPUV exposure. © 2009 American Institute of Physics.
Scientific journal
DOI：https://doi.org/10.1063/1.3129522Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=66549087008&origin=inwardScopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=66549087008&origin=inwardDOI ID：10.1063/1.3129522,
ISSN：0021-8979,
SCOPUS ID：66549087008 Two-dimensional patterning of colloidal crystals by means of lateral autocloning in edge-patterned cells Akira Emoto; Tadayoshi Kamei; Tatsutoshi Shioda; Nobuhiro Kawatsuki; Hiroshi Ono
Journal of Applied Physics,
Volume：105,
Number：12, 2009,
[Reviewed]We report the experimental results of two-dimensional patterning of colloidal crystals using edge-patterned cells. Solvent evaporation of a colloidal suspension from the edge of the cell induces self-organized crystallization of spherical colloidal particles. From a reservoir of colloidal suspension in the cell, different colloidal suspensions are injected repetitively. An edge-patterned substrate is introduced into the cell as an upper substrate. As a result, different colloidal crystals are alternately stacked in the lateral direction according to the edge pattern. The characteristics of cloning formation are specifically showed including deformations from the original pattern. This two-dimensional patterning of three-dimensional colloidal crystals by means of lateral autocloning is promising for the development of photonic crystal arrays for use in optic and photonic devices. © 2009 American Institute of Physics.
International conference proceedings
DOI：https://doi.org/10.1063/1.3151710Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=67650269800&origin=inwardScopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=67650269800&origin=inwardDOI ID：10.1063/1.3151710,
ISSN：0021-8979,
SCOPUS ID：67650269800 Large birefringence and polarization holographic gratings formed in photocross-linkable polymer liquid crystals comprising bistolane mesogenic side groups Akira Emoto; Taro Matsumoto; Ayumi Yamashita; Tatsutoshi Shioda; Hiroshi Ono; Nobuhiro Kawatsuki
Journal of Applied Physics,
Volume：106,
Number：7, 2009,
[Reviewed]Polarization gratings with large birefringence are formed in photoreactive polymer liquid crystals with bistolane moiety and terminal cinnamic acid moiety by the use of polarized ultraviolet interference light and subsequent annealing. The polarized ultraviolet light causes the axis-selective photoreaction between the cinnamic acid groups and subsequent annealing induce the reorientation of peripheral molecules without cross-linking along the cross-linked groups. Long bistolane mesogenic moiety exhibits large birefringence in comparison with a biphenyl mesogenic moiety, the value of the induced birefringence in the bistolane mesogenic liquid crystalline (LC) polymer is strongly dependent on both the grating constant and the wavelength of the reconstruction light. © 2009 American Institute of Physics.
Scientific journal
DOI：https://doi.org/10.1063/1.3234385Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=70350102368&origin=inwardScopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=70350102368&origin=inwardDOI ID：10.1063/1.3234385,
ISSN：0021-8979,
SCOPUS ID：70350102368 Reconstruction of polarized optical images in two- and three-dimensional vector holograms Hiroshi Ono; Kakeru Suzuki; Tomoyuki Sasaki; Takanori Iwato; Akira Emoto; Tatsutoshi Shioda; Nobuhiro Kawatsuki
Journal of Applied Physics,
Volume：106,
Number：8, 2009,
[Reviewed]In the present paper, we extensively study the optical diffraction in two- and three-dimensional vector holograms and demonstrate the reconstruction of polarized optical images recorded in azobenzene-containing amorphous polymers (AP) and polymer-dissolved liquid-crystalline composites (PDLCC). The polarization states of the interference light are not modulated in the isotropic AP films, while modulated in the anisotropic PDLCC films. The information of the polarized optical image is recorded as the polarization induced anisotropy in the AP and PDLCC medium and is reconstructed as the polarized optical images. The theoretical consideration well explained the characteristics of the reconstructed polarized optical images from both two- and three-dimensional vector holograms. © 2009 American Institute of Physics.
Scientific journal
DOI：https://doi.org/10.1063/1.3247974Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=70350702561&origin=inwardScopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=70350702561&origin=inwardDOI ID：10.1063/1.3247974,
ISSN：0021-8979,
SCOPUS ID：70350702561 High-resolution spectroscopy combined with optical frequency comb and heterodyne detection method Tatsutoshi Shioda; Kenichiro Fujii; Ken Kashiwagi; Takashi Kurokawa
Optics InfoBase Conference Papers,
Volume：27,
Number：7,
First page：1487,
Last page：1491, 2009
We have proposed high resolution spectroscopy based on an optical frequency comb and heterodyne detection method, whose measurement frequency range has already achieved to be 3 THz (1530nm~1560nm) with a spectral resolution of less than 1 MHz. Also, the absolute frequency axis is guaranteed less than 1MHz. In this presentation, we will show the experimental results including dynamic range of the proposed system. © 2009 Optical Society of America.
International conference proceedings
DOI：https://doi.org/10.1364/cleo.2009.cmii3Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85088718357&origin=inwardScopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=85088718357&origin=inwardDOI ID：10.1364/cleo.2009.cmii3,
ISSN：0740-3224,
eISSN：2162-2701,
SCOPUS ID：85088718357 Generation of 100-Gb/s packets having 8-bit return-to-zero patterns using an optical pulse synthesizer with a lookup table Yosuke Tanaka; Ryo Kobe; Tatsutoshi Shioda; Hiroyuki Tsuda; Takashi Kurokawa
IEEE Photonics Technology Letters,
Volume：21,
Number：1,
First page：39,
Last page：41, 2009,
[Reviewed]Real-time generation and switching of 100-Gb/s optical packets with 8-bit return-to-zero pulse patterns was realized by constructing a lookup table of the control signal for use by an optical pulse synthesizer. The resulting packet patterns agreed well with the design specifications. The reproducibility of a packet pattern for a given control current was also confirmed. © 2009 IEEE.
IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, English, Scientific journal
DOI：https://doi.org/10.1109/LPT.2008.2007914Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=71249135948&origin=inwardScopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=71249135948&origin=inwardDOI ID：10.1109/LPT.2008.2007914,
ISSN：1041-1135,
SCOPUS ID：71249135948,
Web of Science ID：WOS:000263480100013 Multicarrier light source with 50 GHz spacing and its application in dense wavelength division multiplexing system Yosuke Tanaka; Yu Matsunaga; Takahiro Hoshi; Tatsutoshi Shioda; Takashi Kurokawa
Japanese Journal of Applied Physics,
Volume：48,
Number：9 Part 3,
First page：09LF04, 2009
We developed a multicarrier light source with a 50GHz spacing using a 25-GHz-spacing comb generator and 50-GHz-spacing comb filter. The comb generator was composed of a dual-drive Mach-Zehnder (MZ) modulator with push-pull operation and a phase modulator (PM). The MZ modulator and PM were overdriven at 12.5GHz and at a harmonic of 25 GHz, respectively. We produced 23 comb lines with a flatness below 1.7 dB, which were demultiplexed to produce 11 channel carriers. The relative intensity noise for each carrier was almost equal to that of the seed laser diode (LD). The crosstalk between neighboring channels was less than -35 dB. It was also confirmed that our comb generator is independent of the wavelength of the seed LD and can cover approximately one hundred channels of the entire C-band with eight seed LDs. Experiments on transmission over 100km achieved a bit error rate of 10-12 for the 10 Gbps non-return-to-zero signal. © 2009 The Japan Society of Applied Physics.
English, Scientific journal
DOI：https://doi.org/10.1143/JJAP.48.09LF04Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=77952700315&origin=inwardScopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=77952700315&origin=inwardDOI ID：10.1143/JJAP.48.09LF04,
ISSN：0021-4922,
eISSN：1347-4065,
SCOPUS ID：77952700315 Fiber transmission characteristics of optical short pulses generated by optical pulse synthesizer Ken Kashiwagi; Yuichiro Kodama; Ryo Kobe; Tatsutoshi Shioda; Yosuke Tanaka; Takashi Kurokawa
Japanese Journal of Applied Physics,
Volume：48,
Number：9 Part 3,
First page：09LF02, 2009
In this study, we experimentally characterize optical short-pulse transmission through single-mode fibers. The initial pulses were precisely generated by an optical pulse synthesizer. The optical pulse synthesizer provides line-by-line phase and intensity modulations to individual channels in optical frequency combs and generates precise arbitral pulses. Pulse shaping enables the experimental evaluation of pulse transmission along the fibers under various initial pulse conditions, and the pulse evolution of Gaussian and sech2 pulses through standard single-mode fibers (SMFs) was experimentally investigated. The sech2 pulses had smaller pulse broadening and distortion than the Gaussian ones at the same pulse width and peak power. The sech2 pulses nearly maintained their initial time bandwidth products (TBPs). The required pulse peak power for soliton transmission matched the theoretical value. © 2009 The Japan Society of Applied Physics.
English, Scientific journal
DOI：https://doi.org/10.1143/JJAP.48.09LF02Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=77952695485&origin=inwardScopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=77952695485&origin=inwardDOI ID：10.1143/JJAP.48.09LF02,
ISSN：0021-4922,
eISSN：1347-4065,
SCOPUS ID：77952695485 Supercontinuum comb generation using optical pulse synthesizer and highly nonlinear dispersion-shifted fiber Samuel Choi; Naoyuki Tamura; Ken Kashiwagi; Tatsutoshi Shioda; Yosuke Tanaka; Takashi Kurokaway
Japanese Journal of Applied Physics,
Volume：48,
Number：9 Part 3, 2009
We propose a novel supercontinuum (SC) generation technology using an optical pulse synthesizer and highly nonlinear dispersion-shifted fiber. The optical pulse synthesizer enables us to reshape seed pulses optimized for broadband SC generation. 25.0 and 12.5GHz SC combs were successfully generated by propagating synthesized seed pulses in the highly nonlinear fiber. We investigated how seed pulse conditions including shape, peak power, repetition rate, and center wavelength affect SC spectral bandwidth. We also evaluated interferometric signal waveforms from a Michelson interferometer using the generated SC comb as the light source. Interferometric peak width improved to 35.5 μm when peak power reached 7.9W for the Gaussian pulse-based SC comb. Numerical simulation results almost agreed with experimental results. The difference between SC combs generated from Gaussian and sech2 pulses was confirmed by the simulations. © 2009 The Japan Society of Applied Physics.
Scientific journal
DOI：https://doi.org/10.1143/JJAP.48.09LF01Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=77952683887&origin=inwardScopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=77952683887&origin=inwardDOI ID：10.1143/JJAP.48.09LF01,
ISSN：0021-4922,
eISSN：1347-4065,
SCOPUS ID：77952683887,
Web of Science ID：WOS:000270565200021 Light wave propagation and Bragg diffraction in thick polarization gratings Hiroshi Ono; Takuya Sekiguchi; Akira Emoto; Tatsutoshi Shioda; Nobuhiro Kawatsuki
Japanese Journal of Applied Physics,
Volume：47,
Number：10 PART 1,
First page：7963,
Last page：7967, Oct. 2008
Light wave propagation in thick polarization gratings has been studied using the finite-difference time-domain (FDTD) method. The diffraction properties of the polarization Bragg gratings were strongly dependent on both the polarization state and incident angle of the probe beam. These characteristics were well explained by the FDTD calculation and the subsequent Fourier transformation. The FDTD calculation also revealed the light electric field near and/or in the polarization Bragg gratings. © 2008 The Japan Society of Applied Physics.
Scientific journal
DOI：https://doi.org/10.1143/JJAP.47.7963Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=62249153908&origin=inwardScopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=62249153908&origin=inwardDOI ID：10.1143/JJAP.47.7963,
ISSN：0021-4922,
eISSN：1347-4065,
SCOPUS ID：62249153908 Analog and digital optical pulse synthesizers using arrayed-waveguide gratings for high-speed optical signal processing Hiroyuki Tsuda; Yosuke Tanaka; Tatsutoshi Shioda; Takashi Kurokawa
Journal of Lightwave Technology,
Volume：26,
Number：6,
First page：670,
Last page：677, Mar. 2008,
[Reviewed]In this paper, analog and digital optical pulse synthesizers using high-resolution arrayed-waveguide gratings (AWG) have been developed. The analog type of optical synthesizer consists of an AWG with an integrated 45°, curved-surfaced mirror, a 4-f lens system, and an optically addressable spatial light modulator. The effective frequency resolution is 14.5 GHz. A dispersion compensation experiment is successfully carried out and a transform-limited short pulse has been obtained. This digital type of optical synthesizer comprises 30 frequency separated channels with a spacing of 12.5 GHz, where each channel includes an amplitude modulator and a phase modulator. The rectangular-shaped pulse is generated with this pulse synthesizer, together with a 12.5-GHz-spacing, optical frequency comb. The synthesizer can generate an optical pulse with any waveform. Moreover, using periodic characteristics of the pulse synthesizer, a 250-GHz repetition rate pulse train was generated, in combination with an ultrawideband, waveguide type of Fabry-Perot electrooptic modulator. © 2008 IEEE.
English, Scientific journal
DOI：https://doi.org/10.1109/JLT.2007.916580Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=42649093834&origin=inwardScopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=42649093834&origin=inwardDOI ID：10.1109/JLT.2007.916580,
ISSN：0733-8724,
CiNii Articles ID：80019492655,
SCOPUS ID：42649093834 Frequency scanning spectroscopy of optical frequency comb with high-resolution on an absolute frequency axis Tatsutoshi Shioda; Takayoshi Mori; Kenichiro Fujii; Yosuke Tanaka; Takashi Kurokawa
Optics InfoBase Conference Papers,
First page：2229,
Last page：2230, 2008
We propose high resolution spectroscopy based on a single-sideband optical modulator and an optical frequency comb technology. It has been confirmed experimentally that the spectral resolution and the frequency measurement range was digit of 1 MHz (10-5 nm) and 1 THz (10 nm), which is corresponding to the comb bandwidth, respectively. © 2008 Optical Society of America.
IEEE, English, International conference proceedings
DOI：https://doi.org/10.1109/QELS.2008.4552563Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84898640447&origin=inwardScopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=84898640447&origin=inwardDOI ID：10.1109/QELS.2008.4552563,
eISSN：2162-2701,
SCOPUS ID：84898640447,
Web of Science ID：WOS:000260498401105 Application of faraday rotator reflector and faraday rotator transmitter to profilometry and tomography Tatsutoshi Shioda; Daisuke Moteki; Samuel Choi; Yosuke Tanaka; Takashi Kurokawa
Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers,
Volume：46,
Number：10 A,
First page：6848,
Last page：6852, Oct. 2007
The polarization compensation of a Faraday rotator reflector was quantitatively measured while applying mechanical stress to an optical fiber. A novel device called a Faraday rotator transmitter was developed to illuminate a sample. It was confirmed that the installation of both a Faraday rotator reflector and a Faraday rotator transmitter in a fiber-optic interferometer greatly improves the accuracy of film thickness measurements compared with measurements obtained using an interferometer that employed polarization- maintaining optical fibers. © 2007 The Japan Society of Applied Physics.
Scientific journal
DOI：https://doi.org/10.1143/JJAP.46.6848Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=35348902457&origin=inwardScopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=35348902457&origin=inwardDOI ID：10.1143/JJAP.46.6848,
ISSN：0021-4922,
eISSN：1347-4065,
SCOPUS ID：35348902457,
Web of Science ID：WOS:000250266800082 Frequency-comb-based interference microscope with a line-type image sensor Samuel Choi; Tatsutoshi Shioda; Yosuke Tanaka; Takashi Kurokawa
Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers,
Volume：46,
Number：10 A,
First page：6842,
Last page：6847, Oct. 2007,
[Reviewed]We present a frequency-comb-based interferometric microscope using a broadband comb light source and a line-type image sensor for profilometry and optical tomography. A waveguide-type frequency comb generator and wavelength equalizer were introduced to broaden the comb spectrum. In this paper, we demonstrate the surface profilometry of a coin and the observation of a cross-sectional tomography image of transparent glass. The three-dimensional images were captured using a line-type image sensor without any mechanical moving parts with a frequency interval variation of 25 GHz. The dynamic range in the depth direction was about 1.4 mm and the measurement resolution was 35 p.m. The standard deviation of seven thickness measurements was 5 μm. © 2007 The Japan Society of Applied Physics.
Scientific journal
DOI：https://doi.org/10.1143/JJAP.46.6842Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=35348861267&origin=inwardScopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=35348861267&origin=inwardDOI ID：10.1143/JJAP.46.6842,
ISSN：0021-4922,
eISSN：1347-4065,
SCOPUS ID：35348861267,
Web of Science ID：WOS:000250266800081 Polarization fluctuation suppression and sensitivity enhancement of an optical correlation sensing system H. B. Song; T. Suzuki; T. Fujimura; K. Nonaka; T. Shioda; T. Kurokawa
Measurement Science and Technology,
Volume：18,
Number：10,
First page：3230,
Last page：3234, Oct. 2007,
[Reviewed]Based on the optical pulse correlation measurement and differential detection technique, an optical fibre sensor with high time resolution has been developed. However, due to the birefringence in single mode fibre induced by the uneven thermal effect, polarization fluctuation in the correlation signal was observed. In order to suppress the polarization fluctuation in the correlation sensing system, a polarization-suppressed optical correlation sensing system is proposed by utilizing the birefringence compensation approach in a retraced fibre path using Faraday rotator mirror elements. The polarization fluctuation of the output correlation signals is suppressed by more than 15 dB. The results of temperature experiment indicate that the linearity between the temperature and differential signal is further improved. With the reflection of the mirror, a double-pass monitoring is established, which significantly enhances the sensitivities of the sensing system to temperature and strain. © 2007 IOP Publishing Ltd.
Scientific journal
DOI：https://doi.org/10.1088/0957-0233/18/10/S27Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=36749019656&origin=inwardScopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=36749019656&origin=inwardDOI ID：10.1088/0957-0233/18/10/S27,
ISSN：0957-0233,
eISSN：1361-6501,
SCOPUS ID：36749019656 Resolution and noise factor of distance measurement using two-photon absorption process in photodetector Yosuke Tanaka; Tatsutoshi Shioda; Mitsuo Takeda; Takashi Kurokawa
Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers,
Volume：46,
Number：8 A,
First page：5331,
Last page：5337, Aug. 2007
In this paper, we investigate the resolution, accuracy, and noise factor of distance measurement using intensity-modulated light and a photodetector with two-photon absorption (TPA) characteristics. Distance resolution and measurement accuracy are clarified theoretically and experimentally in terms of the sweeping range and the scanning step of the intensity-modulation frequency. The theory of accuracy improvement by signal processing known as the "Fourier transform method" is experimentally confirmed for the first time. The influence of a photodetector's temperature on measurement resolution is also made clear by the experiments. A high resolution is achieved by controlling the photodetector at a low temperature, which is explained from the temperature dependence of TPA sensitivity in the photodetector. In addition to these investigations, we discuss the advantage of the TPA-based distance measurement over other conventional methods such as optical time domain reflectometry from the viewpoints of cost and measurement performance. © 2007 The Japan Society of Applied Physics.
English, Scientific journal
DOI：https://doi.org/10.1143/JJAP.46.5331Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=34547854760&origin=inwardScopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=34547854760&origin=inwardDOI ID：10.1143/JJAP.46.5331,
ISSN：0021-4922,
eISSN：1347-4065,
CiNii Articles ID：150000049232,
SCOPUS ID：34547854760 1 MHz-resolution spectroscopy based on light frequency sweeping using a single-sideband optical modulator Tatsutoshi Shioda; Takeshi Yamamoto; Tatsuya Sugimoto; Yosuke Tanaka; Kaoru Higuma; Takashi Kurokawa
Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers,
Volume：46,
Number：6 A,
First page：3626,
Last page：3629, Jun. 2007
We propose high-resolution spectroscopy based on laser light frequency sweeping using an optical single-sideband modulator. It has been confirmed experimentally that the frequency stability of the light source and high-speed scanning are critical for obtaining high resolutions of up to 1 MHz. © 2007 The Japan Society of Applied Physics.
English, Scientific journal
DOI：https://doi.org/10.1143/JJAP.46.3626Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=34547842110&origin=inwardScopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=34547842110&origin=inwardDOI ID：10.1143/JJAP.46.3626,
ISSN：0021-4922,
eISSN：1347-4065,
CiNii Articles ID：150000048861,
SCOPUS ID：34547842110 Frequency-comb-based interferometer for profilometry and tomography Choi Samuel; Mitsufumi Yamamoto; Daisuke Moteki; Tatsutoshi Shioda; Yosuke Tanaka; Takashi Kurokawa
Optics Letters,
Volume：31,
Number：13,
First page：1976,
Last page：1978, Jul. 2006,
[Reviewed]Novel interferometry technique using a frequency-comb light source is proposed for surface profilometry and tomography of discontinuous objects. Surface profile measurement is performed by sweeping the comb interval frequency without mechanical scanning. Step heights of 0.5 and 1.0mm are successfully measured by use of the scheme with 9 µm accuracy. © 2006 Optical Society of America.
English, Scientific journal
DOI：https://doi.org/10.1364/OL.31.001976Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=33749342416&origin=inwardScopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=33749342416&origin=inwardDOI ID：10.1364/OL.31.001976,
ISSN：0146-9592,
eISSN：1539-4794,
CiNii Articles ID：80019047219,
PubMed ID：16770404,
SCOPUS ID：33749342416 Waveform-controllable optical pulse generation using an optical pulse synthesizer D. Miyamoto; K. Mandai; T. Kurokawa; S. Takeda; T. Shioda; H. Tsuda
IEEE Photonics Technology Letters,
Volume：18,
Number：5,
First page：721,
Last page：723, Mar. 2006
We have proposed an optical pulse synthesizer comprising of optical modulators and an arrayed waveguide grating. This system can generate arbitrary waveform pulses in combination with a broad-band optical frequency comb. We achieved the generation of the Gaussian pulses with a width of 4.7 ps, double-Gaussian pulses, and rectangular-shaped pulses by arbitrary waveform pulse synthesis, at the high repetition rate of 10 GHz. © 2006 IEEE.
Scientific journal
DOI：https://doi.org/10.1109/LPT.2006.870080Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=33748777041&origin=inwardScopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=33748777041&origin=inwardDOI ID：10.1109/LPT.2006.870080,
ISSN：1041-1135,
SCOPUS ID：33748777041 Common-path achromatic interferometer-coronagraph: Nulling of polychromatic light Alexander V. Tavrov; Yosuke Kobayashi; Yosuke Tanaka; Tatsutoshi Shioda; Yukitoshi Otani; Takashi Kurokawa; Mitsuo Takeda
Optics Letters,
Volume：30,
Number：17,
First page：2224,
Last page：2226, Sep. 2005,
[Reviewed]A three-dimensional common-path interferometer is proposed, which can achromatically null out an on-axis source while it maintains the detectability of an off-axis source. A geometric phase in the three-dimensional interferometer introduces an achromatic π-phase shift to the light from the on-axis source, such that destructive interference nulls out the axial light at one of the ports of the interferometer. Light from the off-axis source, which is exempt from the π-phase shift, comes out from both ports with equal intensity. The common-path scheme makes the system highly immune to environmental disturbances. © 2005 Optical Society of America.
English, Scientific journal
DOI：https://doi.org/10.1364/OL.30.002224Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=25144431981&origin=inwardScopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=25144431981&origin=inwardDOI ID：10.1364/OL.30.002224,
ISSN：0146-9592,
CiNii Articles ID：30011699421,
SCOPUS ID：25144431981 Orientation of liquid crystal molecules evaporated onto rubbed and photoaligned polymer surfaces Tatsutoshi Shioda; Yoshinori Okada; Yoichi Takanishi; Ken Ishikawa; Byoungchoo Park; Hideo Takezoe
Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers,
Volume：44,
Number：5 A,
First page：3103,
Last page：3110, May 2005
Second-harmonic generation (SHG) and polarized ultraviolet-visible (UV-VIS) absorption have been used to study the orientational distribution function of 5CB (4′-n-pentyl-4-cyanobiphenyl) liquid crystal (LC) molecules adsorbed on rubbed and photoaligned photoisomerizable polyamic acid layers. The simultaneous analysis of SHG and polarized UV-VIS absorption data using the maximum entropy method shows that the anisotropic distribution of 5CB molecules along the rubbing direction tilts up from the surface plane as the molecular density increases. More interestingly, the anisotropy is relatively low at the first stage of the evaporation and becomes gradually pronounced, indicating an important role played by the long-range intermolecular interaction among LC molecules for LC surface alignment. No orientation formation of non-liquid crystalline 4CB (4′-n-butyl-4-cyanobiphenyl) molecules on the treated surfaces supports this conclusion. It is important to emphasize that a relatively small fraction of molecules contribute to give a polar order, but the rest form dimers even at the early stage of the evaporation. This tendency is particularly marked on the photoaligned surface; no SHG activity arises irrespective of the amount of evaporated molecules. © 2005 The Japan Society of Applied Physics.
Scientific journal
DOI：https://doi.org/10.1143/JJAP.44.3103Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=22544474194&origin=inwardScopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=22544474194&origin=inwardDOI ID：10.1143/JJAP.44.3103,
ISSN：0021-4922,
SCOPUS ID：22544474194 Optical reflectometry for 10 km fibers based on two photon absorption Masanori Akiyama; Soichiro Imoto; Tatsutoshi Shioda; Yosuke Tanaka; Takashi Kurokawa
Pacific Rim Conference on Lasers and Electro-Optics, CLEO - Technical Digest,
Volume：2005,
First page：1586,
Last page：1587, 2005
We successfully measured the distance of 10 km optical fibers with an accuracy of 10-7. Furthermore, two reflection points with 2.5 m separating over 10 km far away was also successfully resolved.
IEEE, English, International conference proceedings
DOI：https://doi.org/10.1109/CLEOPR.2005.1569824Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=33847101462&origin=inwardScopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=33847101462&origin=inwardDOI ID：10.1109/CLEOPR.2005.1569824,
SCOPUS ID：33847101462,
Web of Science ID：WOS:000236757900456 Orientational transition of a bent-core dopant in an anticlinic liquid crystal matrix Min Hua Zhu; M. R. Dodge; Tatsutoshi Shioda; Charles Rosenblatt; Dallas D. Parker; Julie M. Kim; Mary E. Neubert
Liquid Crystals,
Volume：31,
Number：10,
First page：1381,
Last page：1386, Oct. 2004
Small quantities of the bent-core mesogen P-7PIMB were dissolved in an anticlinic liquid crystal consisting of a mixture of left- and right-handed TFMHPOBC, with enantiomer excess X = 0.2. For bent-core concentrations above C = 3 wt %, differential scanning calorimetry shows the disappearance of the higher temperature synclinic phase, as well as the appearance of a new peak at a low temperature Tc. Polarized infrared absorption measurements indicate that the new DSC peak is due to an orientational transition of the bent-core molecules, analogous to the transition previously observed in a smectic A matrix. For T > Tc the plane of the bent-core molecules lies in the tilt plane of the anticlinic matrix, with the arrow (the symmetry axis) of the bent-core molecules parallel to the smectic layers. For T < Tc we deduce that the bent-core molecules lie within a single smectic layer, with the polar tilt of the arrow approximately equal to the polar tilt of the TFMHPOBC molecule and the vector connecting the two ends of the bent-core molecule perpendicular to the anticlinic tilt plane. Additionally, Tc was found to be an increasing function of bent-core concentration.
Scientific journal
DOI：https://doi.org/10.1080/02678290412331293378Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=4944222731&origin=inwardScopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=4944222731&origin=inwardDOI ID：10.1080/02678290412331293378,
ISSN：0267-8292,
SCOPUS ID：4944222731 Achromatic coronagraph based on out-of-plane common-path nulling interferometer Alexander V. Tavrov; Yosuke Tanaka; Tatsutoshi Shioda; Takashi Kurokawa; Mitsuo Takeda
Proceedings of SPIE - The International Society for Optical Engineering,
Volume：5491,
Number：PART 2,
First page：824,
Last page：830, 2004
3D common-path interferometer is proposed to obtain achromatic nulling for star coronagraphy. Common-path scheme compensates optical path difference (OPD) effectively and is stable to mechanical vibrations. 3D ray geometry involves polarization rotations ±90° in each interferometer arm and results in achromatic 180° phase shift for destructive interference for on-axial source. The interferometer throughput is obtained at nearly 100% for entire polarized light and nearly 50/50 ratio of light energy is split between Bright and Nulled ports for off-axial source. Theory, simulations and preliminary breadboard experiments are shown in reasonable agreement.
International conference proceedings
DOI：https://doi.org/10.1117/12.550759Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=11144283710&origin=inwardScopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=11144283710&origin=inwardDOI ID：10.1117/12.550759,
ISSN：0277-786X,
SCOPUS ID：11144283710 Step-wise Fréedericksz transition in a nematic liquid crystal Tatsutoshi Shioda; Bing Wen; Charles Rosenblatt
Journal of Applied Physics,
Volume：94,
Number：12,
First page：7502,
Last page：7504, Dec. 2003
A step-wise Fre′edericksz transition in a nematic liquid crystal was studied. It was shown that the intensity-voltage profile above the Fre′edericksz threshold voltage may exhibit a shoulder by controlling the anchoring strength on a pixel-by-pixel basis. The two glass substrates coated with a semitransparent layer of electrically conducting indium-tin oxide were cleaned consecutively in detergent, water, acetone and ethanol. It was found that at highest temperature, δT=0.8°C, the intensity-voltage curve exhibits a profile typical for a Fre′edericksz transition in which both substrates were characterized by a spatially uniform anchoring strength coefficient.
Scientific journal
DOI：https://doi.org/10.1063/1.1629389Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=0346935283&origin=inwardScopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=0346935283&origin=inwardDOI ID：10.1063/1.1629389,
ISSN：0021-8979,
SCOPUS ID：0346935283 Experimental determination of molecular polarizability anisotropy of nematogens by depolarized Rayleigh light scattering Kazuhiro Yokota; Tatsutoshi Shioda; Michi Nakata; Yoichi Takanishi; Ken Ishikawa; Hideo Takezoe; Masamitsu Ishitobi; Chizu Sekine
Liquid Crystals,
Volume：30,
Number：6,
First page：697,
Last page：700, Jun. 2003
The anisotropy of molecular polarizability Δα of several nematogens has been determined by depolarized Rayleigh light scattering. The experimentally determined values were found to be noticeably smaller than those obtained by MOPAC calculation. Δα values determined from order parameter S and refractive indices show reasonably good agreement with those determined in the present experiment. This result warns us that Δα calculated by MOPAC, particularly at a finite wavelength, may be larger than the true value.
Scientific journal
DOI：https://doi.org/10.1080/02678290310000Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=0037982426&origin=inwardScopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=0037982426&origin=inwardDOI ID：10.1080/02678290310000,
ISSN：0267-8292,
SCOPUS ID：0037982426 Continuous nematic anchoring transition due to surface-induced smectic order Tatsutoshi Shioda; Bing Wen; Charles Rosenblatt
Physical Review E - Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics,
Volume：67,
Number：4,
First page：5,
Last page：417065, 2003
A continuous transition from tilted to homeotropic alignment at an interface is observed at a temperature [Formula presented] for a nematic liquid crystal on cooling toward the nematic–smectic-[Formula presented] phase transition temperature. [Formula presented] is found to depend on the treatment of the substrate. The behavior is examined theoretically in terms of a pair of competing easy axes (homeotropic and planar) and the tilt elasticity associated with the growth of surface-induced smectic order. © 2003 The American Physical Society.
Scientific journal
DOI：https://doi.org/10.1103/PhysRevE.67.041706Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85037255944&origin=inwardScopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=85037255944&origin=inwardDOI ID：10.1103/PhysRevE.67.041706,
ISSN：1063-651X,
SCOPUS ID：85037255944 Liquid crystals align liquid crystals Tatsutoshi Shioda; Yoshinori Okada; Doo Han Chung; Yoichi Takanishi; Ken Ishikawa; Byoungchoo Park; Hideo Takezoe
Japanese Journal of Applied Physics, Part 2: Letters,
Volume：41,
Number：3 A, Mar. 2002
We have investigated the molecular orientation of a liquid crystal (LC), pentylcyanobiphenyl (5CB), evaporated on a rubbed polymer by means of polarized ultraviolet absorption spectroscopy and surface second-harmonic generation. The results unambiguously reveal that the in-plane anisotropy is diminishingly small before the molecules form a monolayer, although films thicker than one monolayer have a finite in-plane anisotropy. This drastic change indicates that LC molecules on rubbed surfaces do not align well without the influence of the intermolecular interaction of LCs. Actually we confirmed that nonliquid-crystalline butylcyanobipheny (4CB) exhibits no orientation on the rubbed polymer surface regardless of thickness.
Scientific journal
DOI：https://doi.org/10.1143/jjap.41.l266Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=0036508652&origin=inwardScopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=0036508652&origin=inwardDOI ID：10.1143/jjap.41.l266,
ISSN：0021-4922,
SCOPUS ID：0036508652 Axial and polar orientational changes by rubbing/photoalignment processes in a liquid crystal alignment layer studied by optical second-harmonic generation T. Shioda; D. H. Chung; Y. Takanishi; K. Ishikawa; B. Park; H. Takezoe
Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers,
Volume：40,
Number：4 A,
First page：2387,
Last page：2390, Apr. 2001
Molecular reorientation by rubbing and photoalignment processes in polymer alignment layer for liquid crystals has been studied by linear optical absorption and surface optical second-harmonic generation. It was found that rubbing produces polar and axial orders in the photoisomerizable polyamic acid (PAA) containing azobenzene groups in the main chain, while photoalignment after rubbing destroys the polar order but is capable of reorienting the PAA main chain without creating further polar order.
Scientific journal
DOI：https://doi.org/10.1143/jjap.40.2387Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=0035301997&origin=inwardScopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=0035301997&origin=inwardDOI ID：10.1143/jjap.40.2387,
ISSN：0021-4922,
SCOPUS ID：0035301997 Polarization characteristics from SFG spectra of clean and regulatively oxidized Ni(100) surfaces adsorbed by propionate and formate Tetsuo Yuzawa; Tatsutoshi Shioda; Jun Kubota; Ken Onda; Akihide Wada; Kazunari Domen; Chiaki Hirose
Surface Science,
Volume：416,
Number：1-2, Oct. 1998
Experiments have been carried out on propionate and formate adsorbed on clean and regulatively oxidized Ni(100) surfaces to scrutinize the notion that the polarization characteristics of infrared-visible sum frequency generation (SFG) signals of molecules on metallic surfaces are different from those due to molecules on insulating surfaces. Both propionate and formate give signals only for p-polarized visible pulses on clean metal and oxygen-saturated surfaces, but signals due to s-polarized visible pulses appeared from the propionate-covered surface as soon as the surface was covered with a monolayer of NiO(100). Vibrational peaks of propionate were located at 2887, 2945, and 2988 cm-1 and were assigned to the symmetric stretching mode of CH2 group, the symmetric stretching mode of CH3 group, and the degenerate stretching mode of CH3 group, respectively. The peak of the surface formate was located at 2948 cm-1 on the clean metal surface, but another band appeared at 2860 cm-1 on oxide-layered surfaces. The causes of the appearance of the (sp) polarization signals by the presence of the NiO layer are discussed. © 1998 Elsevier Science B.V. All rights reserved.
Scientific journal
DOI：https://doi.org/10.1016/S0039-6028(98)00625-6Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=0032180929&origin=inwardScopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=0032180929&origin=inwardDOI ID：10.1016/S0039-6028(98)00625-6,
ISSN：0039-6028,
SCOPUS ID：0032180929
Optical Terahertz Waveform Generation and 1ns Phase Analysis using Coherence Varied Asynchronous Modes with Optical Frequency Comb Synthesizer/Analyzer for Distance Measurement
Daisuke Noso; Mao Nakamura; Ryo Uchiyama; Tatsutoshi Shioda
CLEO2025, May 2025
Frequency Domain Optical Correlation Using DSB Modulation for Arbitrary Ultrafast Optical Waveform Measurement
Sho Ohmori; Ryosuke Suzuki; Kazuma Yamane; Tatsutoshi Shioda
CLEO2025, May 2025
Tomographic Spectroscopy for Multilayer with Complex Refractive Indices,
Shuto Onodera
OPIC2025, Apr. 2025
Generation of Low-Coherence Dual Coms for 3D Distance Measurement
Satoshi Kanai; Yuki Sekiguchi; Kenta Arai; Tatsutoshi Shioda
OPIC2025, Apr. 2025
Arbitrary Optical Waveform Measurement using Frequency Domain Optical Correlation System with Double-Sideband Modulation
Rosuke Suzuki; Sho Ohmori; Tatsutoshi Shioda
The 2024 International Conference on Photonics Solutions (ICPS2024), Dec. 2024
2D single-shot optical frequency comb profilometry for submicron detection
Bao Dinh Thai; Tuan Truong Cong; Tatsutoshi Shioda
The 2024 International Conference on Photonics Solutions (ICPS2024), Dec. 2024
Optical Frequency Comb based Ultra-fast Waveform and Distance Measurements
Tatsutoshi Shioda
The 2024 International Conference on Photonics Solutions (ICPS2024), Dec. 2024, [Invited]
複素屈折率を持つ多層膜に適用可能なトモグラフィック分光法,
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Nov. 2024
2 次元シングルショット OCT を用いた液体表面の形状変化測定
橋本 夕芽; 村澤 聡笑; 小野寺 柊人; 塩田 達俊
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周波数帯域の拡大を実現する干渉制御を利用した周波数領域光相関法
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Nov. 2024
波長 1.5µm 帯低コヒーレンス光源を用いたデュアルコム分光法の原理検証と距離計測に関する研究
田口 大翔; 鈴木 涼介; 金井 聡志; 田邊 寛洋; 関口 優紀; 塩田 達俊
Nov. 2024
PM ファイバーエタロンの2 偏波モードを用いた低コヒーレンスデュアルコムの生成と距離計測応用
金井 聡志; 関口 優紀; 塩田 達俊
Nov. 2024
3×3カプラと狭帯域バンドパスフィルタを用いた波長1550 nm ピコ秒モード同期ファイバレーザー
西浦 匡則; 中村 亮介; 塩田 達俊
Sep. 2024
DSB変調を用いた周波数領域光相関法による超高速光波形計測の原理検証
大森 翔; 鈴木 涼介; 塩田 達俊
Sep. 2024
光周波数コムシンセサイザ／アナライザによるテラヘルツマイクロ波生成と距離計測応用へ向けた基礎検討
能宗大輔; 内山遼; 塩田達俊
Sep. 2024
空間光学系における偏光干渉を用いた低コヒーレンスデュアルコム分光法の提案と距離計測への応用
田邊 寛洋; 関口 優紀; 塩田 達俊
Sep. 2024
Waveform Control of Terahertz Optical Microwave Generation by Optical Frequency Comb Synthesizer/Analyzer and its Application to TOF Distance Measurement
Daisuke Noso; Ryo Uchiyama; Tatsutoshi Shioda
CLEO-PR2024, Aug. 2024
Generation of Terahertz Optical Microwave generation by Optical Frequency Comb Synthesizer/Analyzer and its application to TOF distance measurement
Ryo Uchiyama; Daisuke Noso; Tatsutoshi Shioda
CLEO2024, May 2024
2D Single-shot Spectral-domain Optical Coherence Tomography by Synchronization of pulse light source and camera
Satoe Murazawa; Keito Fukuda; Tatsutoshi Shioda
OPIC2024, Apr. 2024
関口 優紀, 塩田 達俊
関口 優紀; 塩田 達俊
Mar. 2024
光周波数コムシンセサイザ/アナライザにおけるテラヘルツ帯光マイクロ波の波形制御の距離計測応用へ向けた基礎検討
能宗 大輔; 内山 遼; 今井 颯; 塩田 達俊
Dec. 2023
SSB 光変調器を用いた周波数領域光相関法の共通光路化の検討
鈴木涼介; 大森翔; 塩田達俊
Nov. 2023
2次元SD-OCTにおけるシングルショットパルス照射による振動ロバスト性の向上
村澤 聡笑; 福田 渓人; 塩田 達俊
Nov. 2023
2Dシングルショット干渉計を用いた表面形状計測への構造化光の適用
福田 渓人; 村澤 聡笑; 塩田 達俊
Nov. 2023
光周波数コムシンセサイザ/アナライザによるテラヘルツ帯光マイクロ波の発生と距離計測応
内山 遼; 能宗 大輔; 塩田 達俊
Sep. 2023
Single-Shot Measurement of Optical Frequency Comb Synthesizing Ultrafast Arbitrary Waveforms Using Novel Technique of Frequency Domain Optical Correlation
Kaito Fukushi; Ryosuke Suzuki; Tatsutoshi Shioda
CLEO2023, May 2023
周波数領域光相関法の測定原理に則した計算アルゴリズムの検討
鈴木 涼介; 福士 海渡; 塩田 達俊
Mar. 2023
2D シングルショット光断層計測における高速化と広い計測範囲の両立
福田 渓人; 村澤 聡笑; 塩田 達俊
Mar. 2023
超短パルスレーザーを発生する光ファイバモジュール
西浦 匡則; 影山 陵; 中村 亮介; 塩田 達俊
Jan. 2023
6.5 nJ, 20 MHz compact SESAM-free al-PM ultra-short pulse fiber seed laser pumped by a single butterfly laserdiode
Masanori Nishiura; Ryo Kageyama; Ryosuke Nakamura; Tatsutoshi Shioda
SPIE Photonics West2023, Jan. 2023
Single-shot Ultrafast Optical Waveform Measurement System
Tatsutoshi Shioda
Optics & Photonics Taiwan International Conference (OPTIC), Dec. 2022
Compact NALM-Based Yb Fiber Laser at 1064 nm
Masanori Nishiura; Ryo Kageyama; Ryosuke Nakamura; Tatsutoshi Shioda
OPTICA Laser Congress and exhibition, Dec. 2022
2Dシングルショット光断層計測における振動ロバスト性向上と高感度化
福田 渓人; 塩田 達俊
Nov. 2022
FSRの異なるエタロン2台を用いた低コヒーレンスコム干渉による距離計測
関口 優紀; 高瀬 博章; 横地 界斗; 塩田 達俊
Nov. 2022
周波数領域光相関法と2逓倍変調を用いた光周波数コム合成信号の解析
福士 海渡; 鈴木 涼介; 塩田 達俊
Nov. 2022
光周波数コムとヘテロダイン検波による光ファイバーブリュアン温度計測
小野 拓真; 田中 洋介; 塩田 達俊
Nov. 2022
スーパーコンティニウム光の縦モード間ビート信号の位相解析による屈折率計測
青山 直樹; 塩田 達俊
Nov. 2022
ピコ秒前後で変化する光電界の解析
塩田 達俊
Nov. 2022
2逓倍変調を用いた周波数領域光相関システムによる超高速光波形計測の検討
福士 海渡; 青山 直樹; 鈴木 涼介; 塩田 達俊
Sep. 2022
光周波数コムとヘテロダイン検波を利用したブリュアンスペクトル計測
小野 拓真; 田中 洋介; 塩田 達俊
Sep. 2022
光マイクロ波の位相検波による屈折率計測の基礎検討
青山 直樹; 土屋 直彰; 塩田 達俊
Sep. 2022
2波長バンドパスフィルタを用いたシングルゲイン8の字型ファイバレーザー
影山 稜; 西浦 匡則; 謝 宜達; 塩田 達俊; 中村 亮介
Sep. 2022
NALM型ファイバレーザー発振器とプリアンプの統合
西浦 匡則; 影山 陵; 塩田 達俊
Sep. 2022
Common Path Frequency Domain Optical Correlation System for Ultrafast Optical Waveform Analysis
Kaito Fukushi; Tatsutoshi Shioda
CLEO-PacificRim2022, Aug. 2022
Brillouin Fiber Sensor Based on Optical Frequency Comb and Heterodyne Detection
Takuma Ono; Yosuke Tanaka; Tatsutoshi Shioda
CLEO-PacificRim2022, Aug. 2022
Investigation of the effect of grating profile on the precision of 2D single-shot comb-based interferometer
Dinh Thai Bao; Keishi Chiba; Truong Cong Tuan; Tatsutoshi Shioda
CLEO-PacificRim2022, Aug. 2022
Phase Sensitive Surface Profile Measurement Using Swept Multigigahertz Supercontinuum Comb
Samuel Choi; Takuro Yamazaki; Hiroshi Hibino; Takamasa Suzuki; Tatsutoshi Shioda
CLEO-PacificRim2022, Aug. 2022
超高速光波形計測へ向けた共通光路周波数領域光相関システム
福士 海渡; 八木 達椰; 塩田 達俊
Mar. 2022
高周波数コムとヘテロダイン検波を利用したブリュアンセンサ
小野 拓真; 田中 洋介; 塩田 達俊
Mar. 2022
低コヒーレンスデュアルコム分光法の提案と距離計測へ向けたシミュレーション
関口 優紀; 高瀬 博章; 高橋 聖基; 横地 界斗; 小笠原 隆行; 塩田 達俊
Mar. 2022
バランス型二波長同時ヘテロダイン検波法による位相計測精度の向上
青山 直樹; 今井 颯; 内山 遼; 塩田 達俊
Mar. 2022
２波長バンドパスフィルタを用いた セルフスタートモード同期ファイバレーザー
西浦 匡則; 塩田 達俊
Jan. 2022, [Invited]
Q周波数領域光相関法を用いた超高速光波形計測
塩田 達俊
Jan. 2022
Research on the effect of the grating profile on the profilometry resolution of the 2D single-shot comb-based interferometer
Dinh Thai Bao; Keishi Chiba; Truong Cong Tuan; Tatsutoshi Shioda
AUN/SEED-Net Joint Regional Conference in Transportation, Energy and Mechanical Manufacturing Engineering, Dec. 2021
figure-8 超短パルスファイバレーザーの数値解析
西浦 匡則; 塩田 達俊
Nov. 2021
周波数領域での高速光波形計測
塩田 達俊
Oct. 2021
K-K解析による多層構造空間分解複素電界分光法の原理実証
梶山 貴弘; 塩田 達俊
Oct. 2021
周波数領域光相関法に向けた変調器の伝搬方向相違性の検討
八木 達椰; 福士 海渡; 塩田 達俊
Oct. 2021
超高速光波形計測のための単一方向に伝搬する共通光路周波数領域光相関システム
福士 海渡; 八木 達椰; 塩田 達俊
Oct. 2021
バランス型2波長同時ヘテロダイン検波法による光位相計測の高感度化の検討
今井 颯; 青山 直樹; 塩田 達俊
Oct. 2021
シングルショット二次元OCTにおける空間光学的バンドパスフィルタを用いた背景光低減
千葉 啓史; 塩田 達俊
Oct. 2021
K-K解析によるSD-OCTを用いた多層構造空間分解複素電界分光法
梶山 貴弘; 塩田 達俊
Sep. 2021
２次元シングルショット OCT の空間位相変調器のステップ長と計測精度の関係
千葉 啓史; 塩田 達俊
Sep. 2021
光周波数コムアナライザによるワンショット超高速任意光波形計測
青山 直樹; 今井 颯; 塩田 達俊
Sep. 2021
周波数領域光相関超高速任意光波形計測の実現に向けた光周波数変調器特性の調査
八木 達椰; 福士 海渡; 塩田 達俊
Sep. 2021
25.6 Tbps Pre-Compensated Waveform Propagation Using Optical Frequency Comb Synthesizer/Analyzer
N. Sultana; H. Tada; H. Imai; T. Shioda
CLEO2021, May 2021
ANDiモード同期ファイバレーザーにおける狭帯域バンドパスフィルタのスロープ依存性”
西浦 匡則; 塩田 達俊
Mar. 2021
Dual-bandpass filter for self-starting mode-locking in All-PM NALM-based fiber laser
Masanori Nishiura; Tatsutoshi Shioda
Photonics West 2021 Digital Forum, Mar. 2021
全正常分散ファイバレーザーのバンドパスフィルタ依存性
紀 里; 西浦 匡則; 塩田 達俊
Jan. 2021
光コムシンセサイザ／アナライザを用いたワンショット超高速任意波形計測
今井 颯; 多田 浩明; ナスリン スルタナ; 青山 直樹; 塩田 達俊
Nov. 2020
スーパーコンティニューム光の縦モード間干渉を利用した屈折率計測
中堀 秀治; 渡部 未来; 塩田 達俊
Nov. 2020
SD-OCTを用いた空間分解複素電界分光法
梶山 貴弘; 郡司 翔平; 唐澤 悠太朗; 塩田 達俊
Nov. 2020
2次元シングルショット光干渉断層計測法のロバスト性向上
阿波根 稔季; 塩田 達俊
Nov. 2020
高速光分散スペクトル計測法と分散した伝播経路中の任意位置における光波形制御システムの提案
青山 直樹; ナスリン スルタナ; 今井 颯; 多田 浩明; 塩田 達俊
Nov. 2020
二次元シングルショット断層計測におけるステップ型空間位相変調器と位置検出精度の関係
千葉 啓史; 塩田 達俊
Nov. 2020
機械的走査のないパルス幅・波長可変モード同期ファイバレーザー
西浦 匡則; 塩田 達俊
Nov. 2020
超高速光波形計測へ向けた周波数領域光相関法の提案
三木 真人; 八木 達椰; 福士 海斗; 今井 颯; 塩田 達俊
Nov. 2020
Q スイッチ誘発波長フィルタを用いた自己始動モード同期
西浦 匡則; 塩田 達俊
Nov. 2020
Measurement Range Extension of an Industrial Tomography and Profilometry Using Comb-less Interferometry
Tuan Cong Truong; Thoa Thi Mac; Tuan Quoc Banh; Tung Thanh Vu; Tatsutoshi Shioda; Thang Toan Vu
Annual International Conference on Material, Machines and Methods for Sustainable Development (MMMS2020), Nov. 2020
スーパーコンティニューム光源の複数モード間干渉を用いた屈折率計測のレンジ拡大
中堀 秀治; 渡部 未来; 塩田 達俊
Sep. 2020
周波数領域光相互相関を用いた超高速光波形計測システムの基礎検討
八木 達椰; 三木 真人; 今井 颯; 多田 浩明; 塩田 達俊
Sep. 2020
単一過渡応答計測のための光周波数コムシンセサイザ/アナライザ
今井 颯; 多田 浩明; 湯田 怜央奈; 三木 真人; 塩田 達俊
Sep. 2020
振動環境下でのシングルショット２次元光干渉断層計測
阿波根 稔季; 塩田 達俊
Sep. 2020
2D Single-shot Optical Coherence Tomography for Measurement Under Vibration Environment
Toshiki Awane; Tatsutoshi Shioda
The CLEO PR 2020, Aug. 2020
Ultra-fast Waveform Measurement in Single-shot Using Optical Frequency Comb Analyzer,
Hayate Imai; Hiroali Tada; Sultana Nasrin; Shioda Tatsutoshi
CLEo2020, May 2020
Scan-less Dispersion Spectroscopy with Single-shot DualHeterodyne Mixing and Optical Frequency Comb
Sultana Nasrin; Hiroaki Tada; Tatsutoshi Shioda
CLEO2020, May 2020
高速光波形計測のための周波数領域光相関法の提案と基礎検討
八木 達椰; 三木 真人; 多田 浩明; 今井 颯; 塩田 達俊
Mar. 2020
振動環境下での高速・非接触２次元シングルショット表面形状計測
阿波根 稔季; トゥアン バン; 塩田 達俊
Mar. 2020
シングルショット超高速波形計測のための高速光周波数コムアナライザ
多田 浩明; 湯田 怜央奈; 今井 颯; 三木 真人; 塩田 達俊
Mar. 2020
1020-1064 nm wavelength-tunable all polarization maintaining mode-locked fiber laser with a programmable optical filter
Masanori Nishiura; Tatsutoshi Shioda
Photonics West 2020, Feb. 2020
波長フレキシブル全PMモード同期Ybファイバレーザ
西浦 匡則; 塩田 達俊
Jan. 2020
周波数軸上での相関を利用した高速波形計測法についての基礎検討
三木 真人; 多田 浩明; 八木 達椰; 塩田 達俊
Dec. 2019
High-speed 2D Single-shot Surface Profilometry for Industrial Inspection under Vibrational Environment
Toshiki Awane; Tuan Q. Banh; Tatsutoshi Shioda
OSA Laser Congress, Oct. 2019
High-speed and Single-shot Waveform Measurement for Elucidation of Irreversible Chemical Reaction Dynamics
Hiroaki Tada; Leona Yuda; Tatsutoshi Shioda
OSA Laser Congress, Oct. 2019
Dispersion Spectrum Measurement using Scan-less Dual-heterodyne Mixing
Nasrin Sultana; Tada Hiroaki; Shioda Tatsutoshi
OSA Laser Congress, Oct. 2019
低コヒーレンス干渉計を用いたトモグラフィック位相屈折率スペクトル計測
唐澤 悠太朗; 郡司 翔平; 塩田 達俊
Sep. 2019
振動環境下での安定な高速２次元シングルショット表面形状計測
阿波根 稔季; 塩田 達俊; バン クォック トゥアン
Sep. 2019
光周波数コムアナライザを用いた超高速光波形計測のシングルショット計測化に向けた基礎検討
多田 浩明; 湯田 怜央奈; 塩田 達俊
Sep. 2019
NALMを用いたモード同期ピコ秒 全PM Ybファイバレーザ
西浦 匡則; 塩田 達俊
Sep. 2019
低コヒーレンス干渉計によるトモグラフィック屈折率計測
唐澤 悠太朗; 郡司 翔平; 塩田 達俊
Mar. 2019
光コム合成／解析法による超高速光波形計測と分散計測
塩田 達俊
Jan. 2019
光領域差動利得信号生成技術の開拓と半透明サンプルの高速低雑音計測への応用
30 Jun. 2022 - 31 Mar. 2024
Grant amount(Total)：6500000, Direct funding：5000000, Indirect funding：1500000
Grant number：22K18790
International collaborative research on highly sensitive fiber optic sensor for early detection of dielectric breakdown signs in power line
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Fund for the Promotion of Joint International Research (Fostering Joint International Research (B)), 07 Oct. 2021 - 31 Mar. 2024
Tokyo University of Agriculture and Technology
Grant amount(Total)：17680000, Direct funding：13600000, Indirect funding：4080000
Grant number：21KK0067
Study of one-shot/long time range/ultrafast optical waveform measurement system using frequency domain optical correlation technique
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (B), 01 Apr. 2021 - 31 Mar. 2024
Saitama University
Grant amount(Total)：17550000, Direct funding：13500000, Indirect funding：4050000
Grant number：21H01837
二光子吸収応答受光系を用いた多点光ファイバ型ベクトル曲げセンサ
01 Apr. 2020 - 31 Mar. 2023
Grant amount(Total)：17810000, Direct funding：13700000, Indirect funding：4110000
Grant number：20H02158
Study of a femtosecond single-shot transient absorption spectroscopy using discretely oscillating optical frequency comb
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Challenging Research (Exploratory), 30 Jun. 2017 - 31 Mar. 2020
Shioda Tatsutoshi, Saitama University
Grant amount(Total)：6500000, Direct funding：5000000, Indirect funding：1500000
We have studied an optical system, which can performs a single-shot phase measurement in the 40 ps time domain by 25 GHz sampling between modes of the 200 GHz optical frequency comb. In case to apply this technology to transient response measurement, wideband and high-resolution phase spectrum measurement and control technology are required to achieve both time resolution and wide time window. A time parallel measurement system has been devised to enable the phase spectrum measurement to be obtained by a phase detection circuit. The amplitude and phase spectra were measured at 375 GHz (25 GHz, 15 modes), and it was experimentally demonstrated that ultrafast optical electric field waveforms with a 2.7 ps resolution and a 40 ps time range can be measured.
Grant number：17K19069
High-speed and high-precision distributed fiber optic sensing based on optical frequency comb
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (B), 01 Apr. 2016 - 31 Mar. 2019
TANAKA Yosuke, Tokyo University of Agriculture and Technology
Grant amount(Total)：16770000, Direct funding：12900000, Indirect funding：3870000
We started this study with the aim of realizing high-speed and high-precision fiber optic sensing by using optical frequency comb that is composed of multiple modes with an equal frequency spacing. The proposed method can perform measurement in short time, because the Brillouin gain spectrum is measured without scanning the frequency of the light source. In addition to simultaneous measurement of Brillouin gain spectrum, the optical sensing based on multimode stimulated Brillouin scattering was demonstrated to be able to perform measurement with a sensitivity three orders higher than the conventional methods. We have also successfully demonstrated multi-point precision fiber optic measurement using fiber Bragg gratings, which is a spin-off of this study.
Grant number：16H04374
Study of Microscopy with Pseudo-comb Interfermetry and high-speed discrete-frequency scanning laser
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (B), 01 Apr. 2016 - 31 Mar. 2019
SHIODA Tatsutoshi, Saitama University
Grant amount(Total)：16900000, Direct funding：13000000, Indirect funding：3900000
The technology for the inspection of the surface profilometry of the product in the manufacturing field was studied. A two-dimensional single-shot miscroscopy, which can measure the distance in the millimeter region with micrometer resolution in the depth direction, was constructed as non-contact measurement using an optical interferometer.Single-shot two-dimensional tomographic images obtained by high-order pseudo-optical comb interference fringes were observed by a CCD with a high volume sampling rate, using an optical comb that can be easily generated as a light source. On the other hand, the fundamental technology of pseudo optical comb interference was developed by developing an ultra-high-speed optical frequency scanning repetition (1 MHz). The repetition rate is faster than the imaging time of CCD and a high-speed discrete wavelength tunable laser, which performs frequency scanning discretely (200 GHz interval) as the light source.
Grant number：16H03879
Study of a femtosecond time-resolution single-shot transition absorption spectroscopy using optical frequency comb
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Challenging Exploratory Research, 01 Apr. 2015 - 31 Mar. 2017
SHIODA Tatsutoshi, Saitama University
Grant amount(Total)：4030000, Direct funding：3100000, Indirect funding：930000
We have developed optical frequency comb (OFC) synthesizer/analyzer, which basically controls the comb lights on a frequency axis.
To apply the previous OFC analyzer to single-shot measurement, it is necessary to use a digitizer whose integration time is required to be the time range for the previous OFC analyzer. It is, however, difficult to prepare an ultrafast digitizer covering several ten GHz frequency band corresponding to the 10 picosecond time region. Thus, we have proposed following two new concepts. For the first problem, 5 ps measurement time region was extended to 40 ps by measuring the amplitude and phase spectra with a sampling mode space of 25 GHz intervals between 200 GHz comb mode interval. For the second problem about the difficulty to prepare the fast-capturing digitizer, the single shot measurement was realized with a 1 GHz digitizer by cutting-out the optical dual-heterodyne spectrum in 40 picoseconds time window from continuously repeated waveforms.
Grant number：15K13372
Spectrograph based on frequency-variable multi-GHz-comb
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (B), 01 Apr. 2014 - 31 Mar. 2017
Kurokawa Takashi, Tokyo University of Agriculture and Technology
Grant amount(Total)：16120000, Direct funding：12400000, Indirect funding：3720000
The purpose of this study is to develop a frequency-variable comb generation technology, which enables frequency shift of all modes of broadband comb with wide mode interval at once. In addition, we explore a novel spectroscopy with broad bandwidth and high resolution introducing the frequency-variable laser comb to a spectrograph.
We confirmed that optical short pulse with 4-ps pulse width and 12.5-GHz repetition rate generated by pulse shaping was frequency-shifted with MHz precision by using a single sideband modulator. After the compression and amplification of the pulse, it was incident on a highly-nonlinear fiber, and we successfully generated a broadband and frequency-variable laser comb ranging from 1100 to 1700 nm. The frequency-variable laser comb was input into the diffraction grating spectrometer and the spectra of low pressure gas and Fabry-Perot filter were obtained with a resolution of 1 MHz.
Grant number：26286057
Wide dynamic range optical measurement using highly intense multi-gigahertz comb
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (B), 01 Apr. 2013 - 31 Mar. 2016
KASHIWAGI Ken; KUROKAWA Takashi; TANAKA Yosuke; SHIODA Tatsutoshi, Tokyo University of Agriculture and Technology
Grant amount(Total)：18460000, Direct funding：14200000, Indirect funding：4260000
In this study, we used an optical frequency comb with wide mode spacing for high dynamic range optical measurement. An optical frequency comb has optical modes at a certain frequency spacing and, generally, the spacing is relatively narrow in the order of 100 MHz. Each lines of such the optical frequency comb has low intensities because the average power is distributed to the large number of the lines. In this study, we used an optical frequency comb whose line-spacing is wider than 10 GHz (multi-gigahertz comb) to obtain high intense comb lines. The high intensity can lead to wide-dynamic-range measurement. To realize the measurement technique, we realized a broadband optical frequency comb with wide mode-spacing and frequency tunability. Finally, we employed the comb as a lightsource for optical measurement.
Grant number：25286065
Investigation of single-shot femto-second time-resolved optical frequency comb analyzer
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Challenging Exploratory Research, 01 Apr. 2013 - 31 Mar. 2015
SHIODA Tatsutoshi, Saitama University
Grant amount(Total)：3900000, Direct funding：3000000, Indirect funding：900000
We have developed a technique called multi-wavelength electric field heterodyne detection on Fourier space that can measure the asymmetrical ultrafast waveforms with high sensitivity. The relative phase between the adjacent peaks of the optical comb are detected by using the reference optical comb. A prototype and operation of the Fourier space light source system was carried out along the following items.
1. The 200GHz optical frequency comb of 32 waves was generated with the seed light source of 25GHz optical frequency comb (256 waves).
2. The pulse train of the optical comb, ie, the electric field spectrum of spectral region was measured in a time of the waveform changing by the digitizer. And it succeeded in reproducing by measuring the waveform within a repetition time by inverse Fourier transformation of the measured light field spectrum.
Grant number：25600114
Study of ultrafast holographic optical frequency comb synthesizer
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Young Scientists (A), 01 Apr. 2011 - 31 Mar. 2014
SHIODA Tatsutoshi
Grant amount(Total)：27430000, Direct funding：21100000, Indirect funding：6330000
We have proposed an ultrafast optical arbitrary waveform synthesizer and analyzer in femtosecond and picosecond time region. Ultrafast waveforms were generated by manipulating the amplitude and phase of a gigahertz optical frequency comb (OFC) using a customized colorless optical synthesizer. The synthesized waveform was analyzed on the frequency axis using a dual-heterodyne mixing. The proposed system has been applied to generate femtosecond pulses and to synthesize composite amplitude-shift and phase-shift keying signals.
Grant number：23686014
Development of frequency and time resolved SNOM using optical frequency comb
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (B), 01 Apr. 2011 - 31 Mar. 2014
ISHIBASHI Takayuki; SHIODA Tatsutoshi, Nagaoka University of Technology
Grant amount(Total)：17680000, Direct funding：13600000, Indirect funding：4080000
We have developed an apertureless SNOM (a-SNOM), and have studied the polarization properties of the a-SNOM. As a result, we have succeeded to obtain a spatial resolution of approximately 10 nm. In addition, we have also succeeded to resolve a SNOM signal and a background signal. FDTD simulation explained our experimental results well, and consequently, we understood electric fields underneath apertureless probes. Furthermore, we developed a system for time-resolved SNOM measurement.
Grant number：23310073
Hybrid type three-dimensional display combining projection type and lenticular type
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (B), 2008 - 2010
TAKAKI Yasuhiro; SHIOTA Tatsutoshi, Tokyo University of Agriculture and Technology
Grant amount(Total)：18720000, Direct funding：14400000, Indirect funding：4320000
In order to realize a natural three-dimensional display which is free from visual fatigue, a large number of images have to be displayed simultaneously. This study proposed a new display system which is a hybrid system combining the lenticular display system and the multi-projection display system. The prototype display that generates 256 images was developed. The accommodation responses of humans to the prototype display were measured and we confirmed that the depth range where the visual fatigue does not occur was enlarged.
Grant number：20360153
Development of spatial resolution and measurement speed of 3-dimensional optical microscopy using optical frequency comb
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Young Scientists (B), 2008 - 2009
SHIODA Tatsutoshi
Grant amount(Total)：4420000, Direct funding：3400000, Indirect funding：1020000
We have developed a arbitrary waveform generator using an optical synthesizer consisting of a nonlinear optical fiber, which was applied for a microscopy. The experimental condition for generating the wideband supercontinuum spectrum was confirmed. The 80 nm spectral band was generated from the 3 nm band comb light source.
Grant number：20760031
光変調器を用いた光周波数掃引による高分解能分光システム
2006 - 2007
Grant amount(Total)：3600000, Direct funding：3600000
Grant number：18760038
Space-Time Multiplexed Natural Three-Dimensional Display
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (B), 2006 - 2007
TAKAKI Yasuhiro; SHIOTA Tatsutoshi, Tokyo University of Agriculture and Technology
Grant amount(Total)：17050000, Direct funding：14800000, Indirect funding：2250000
The new high-density directional (HDD) display using the time-multiplexing technique is proposed to reduce the complexity of the multi-projection system used for the HDD display. The HDD display is a natural three-dimensional display which has been developed to solve the visual fatigue problem caused by the accommodation-vergence conflict. The proposed HDD display consists of multiple time-multiplexing display modules. Each module consists of an LED array, a DMD, lenses, and an aperture array. A number of directional images are displayed by the DMD at a high frame rate and the LED's emit light one after another in synchronization with the DMD. The apertures are arranged two-dimensionally, and their horizontal positions are different. The LED's are arranged in a same way. All directional images displayed by the DMD pass through different apertures. Multiple modules are arranged two-dimensionally with the different horizontal positions and all images are combined by a common lens. A vertical diffuser is used as a display screen to cancel the difference of the vertical display directions. All directional images are superimposed on the vertical diffuser, and are given the different horizontal display directions. Each module generates 15 directional images at a frame rate of 60 Hz. Four modules are combined to display 60 directional images in the different horizontal directions with the angle pitch of 0.31°.
Grant number：18360165
3D microscopy based on optical frequency comb by RF control
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (B), 2006 - 2007
KUROKAWA Takashi; SHIODA Tatsutoshi; TAKEDA Mitsuo, Tokyo University of Agriculture and Technology
Grant amount(Total)：16610000, Direct funding：14900000, Indirect funding：1710000
In our previous report, the optical frequency comb generator consisting of two phase modulators in tandem we used generated the narrow bandwidth of the comb spectrum, only 2 nm, and resulted in the limited resolution up to 300μm. And some noises of many side-lobes appeared around the interferometric peaks due to a rectangular frequency comb spectrum. Furthermore, it took a long time for the data acquisition because the point-to-point scanning was used in a fiber-optic interferometer.
To improve the performance of our previous system, we introduced new functions of a broad band frequency comb and a line-type image sensor to realize a frequency comb-based interferometric microscope. One of the improvements in the proposed system is that a broadband frequency comb spectrum of over 10 nm was obtained by combining a waveguide type-frequency comb generator^<6-8)> consisting of the phase modulator installed in the Fabry-Perot cavity and a subsequent wavelength equalizer^<9)>. The depth resolution is finally improved up to 35 μm, and the side-lobes in the interferometric signals also disappeared. Another important improvement is to realize a high-speed observation of three-dimensional images by the use of a line type-image sensor for capturing a line image in a horizontal direction at a time.
The measurement resolution narrowed finally to 35 μm by introducing the waveguide-type frequency comb generator and the wavelength equalizer. Furthermore, introducing the line image sensor can obtain the simultaneous measurement of the whole horizontal cross sectional image of the interferometric signal. We successfully demonstrated the 3 dimensional surface profilometry of a Japanese 10-yen coin and observation of a cross sectional tomography image of transparent thin films by varying the comb frequency interval without mechanical shift. The dynamic range in the depth direction was about 1.1 mm and the measurement resolution was 35μm. The standard deviation of seven times thickness measurements was 5μm.
Grant number：18360164
Study of coherence tomography based on optical frequency comb
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (B), 2004 - 2005
KUROKAWA Takashi; TANAKA Yosuke; SHIODA Tatsutoshi; TAKEDA Mitsuo, Tokyo University of Agriculture and Technology
Grant amount(Total)：15300000, Direct funding：15300000
A range of techniques, including coherence scanning microscopy, three-dimensional sensing by coherence radar, and scanning white-light interferometry, have been developed for simultaneous measurement of the three-dimensional step height of discontinuous objects and tomographic imaging. These techniques, however, require mechanical scanning with a piezoelectric transducer or a precision translator. Spectral interferometry, on the other hand, potentially offers a powerful means for high-speed absolute threedimensional shape measurement of objects without moving mechanical parts. The practical applicability of such methods, however, remains limited due to the high cost of tunable lasers with sufficiently wide range (e.g., external cavity laser diodes and dye lasers) and the slow speed of data acquisition because of the large number of calculations in the Fourier transform. As an alternative interferometry-based approach, synthesis of the coherence functions has been reported to be suitable for distance measurements. This method involves pseudo-frequency comb generation by frequency modulation of a laser diode. Yet this method is not suitable for surface profilometry because the frequency-comb interval is limited to the order of megahertz.
In this Letter, a novel frequency comb-based interferometry technique for profilometry and tomography is proposed. The optical frequency comb employed by this method can be adjusted simply, allowing interferometry to be performed at frequency intervals of up to gigahertz order. The method is therefore suitable for measurement of absolute distances of several micrometers to several meters without the need for mechanical movement.
Step-height measurement with 9 μm accuracy was successfully performed by sweeping the comb interval frequency. Thickness measurement of a glass plate was also demonstrated. This profilometry method is expected to be useful for both surface profilometry and tomography.
Grant number：16360027
