研究者データベース

鈴木 雅人(スズキ マサト)
工学研究院 応用物理学部門 光波動量子物理工学分野
特任助教

基本情報

所属

  • 工学研究院 応用物理学部門 光波動量子物理工学分野

職名

  • 特任助教

学位

  • 博士(工学)(2016年03月 北海道大学)

研究活動情報

論文

  • Wideband Intermodal Nonlinear Signal Processing With a Highly Nonlinear Few-Mode Fiber
    Georg Rademacher, Ruben S. Luís, Benjamin J. Puttnam, Yoshinari Awaji, Masato Suzuki, Takemi Hasegawa, Hideaki Furukawa, Naoya Wada
    IEEE Journal of Selected Topics in Quantum Electronics 26 4 1 - 7 2020年07月 [査読有り][招待有り]
  • Omar F Anjum, Massimiliano Guasoni, Peter Horak, Yongmin Jung, Masato Suzuki, Takemi Hasegawa, Kyle Bottrill, David J Richardson, Francesca Parmigiani, Periklis Petropoulos
    Optics express 27 17 24072 - 24081 2019年08月19日 [査読有り][通常論文]
     
    We experimentally demonstrate a means to selectively enhance wavelength conversion of WDM channels on a 100 GHz grid exploiting nonlinear effects between the spatial modes of a few mode fiber. The selectivity of parametric gain is obtained by dispersion design of the fiber such that the inverse group velocity curves of the participating modes are parallel and their dispersion is suitably large. We describe both theoretically and experimentally the observed dependence of the idler gain profile on pump mode (quasi) degeneracy.
  • Masato Suzuki, Keisaku Yamane, Kazuhiko Oka, Yasunori Toda, Ryuji Morita
    SCIENTIFIC REPORTS 9 2019年07月 [査読有り][通常論文]
     
    We demonstrate a comprehensive quantitative analysis of vector beam states (VBSs) by using a vector field reconstruction (VFR) technique integrating interferometry and imaging polarimetry, where the analysis is given by a cylindrically polarized Laguerre-Gaussian (LG) mode expansion of VBSs. From test examples of cylindrically polarized LG mode beams, we obtain the complex amplitude distributions of VBSs and perform their quantitative evaluations both in radial and azimuthal directions. The results show that we generated (l, p) = (1, 0) LG radially polarized state with a high purity of 98%. We also argue that the cylindrically polarized LG modal decomposition is meaningful for the detail discussion of experimental results, such as analyses of mode purities and mode contaminations. Thus the VFR technique is significant for analyses of polarization structured beams generated by lasers and converters.
  • Omar F. Anjum, Peter Horak, Yongmin Jung, Masato Suzuki, Yoshinori Yamamoto, Takemi Hasegawa, Periklis Petropoulos, David J. Richardson, Francesca Parmigiani
    APL PHOTONICS 4 2 2019年02月 [査読有り][通常論文]
     
    We report on the design, fabrication, and experimental characterization of germanium-doped graded-index multi-mode fibers that are tailored to achieve broadband operation for the inter-modal Bragg scattering four wave mixing process. First, we show that increasing the core diameter decreases the separation between the pumps and the signal/idler pair. Second, we demonstrate a conversion efficiency bandwidth (7 nm) of more than twice that achieved previously with half the fiber length (50 m). (C) 2018 Author(s).
  • Daiki Soma, Yuta Wakayama, Shohei Beppu, Seiya Sumita, Takehiro Tsuritani, Tetsuya Hayashi, Takuji Nagashima, Masato Suzuki, Masato Yoshida, Keisuke Kasai, Masataka Nakazawa, Hidenori Takahashi, Koji Igarashi, Itsuro Morita, Masatoshi Suzuki
    JOURNAL OF LIGHTWAVE TECHNOLOGY 36 6 1362 - 1368 2018年03月 [査読有り][通常論文]
     
    Space-division multiplexing (SDM) is an attractive technique for dramatically enhancing the transmission capacity in a single optical fiber. Recently, ultradense SDM transmission experiments with a spatial multiplicity of over 100 have been reported by using few mode multicore fibers (FM-MCFs). Considering the maximum capacity of around 100 Tb/s reported in single-mode single-core fiber transmission experiments, the capacity in FM-MCF transmission with more than 100 spatial channels is expected to reach 10 peta-b/s; however, the maximum capacity has been limited to 2 peta-b/s. In this paper, we demonstrate ultradense SDM transmission of 739 WDM 12-Gbd dual polarization-64-quadrature amplitude modulation (QAM)/16-QAM signals over 11.3-km 6-mode 19-core fiber using the C+L band, achieving a record fiber capacity of 10.16 peta-b/s with an aggregate spectral efficiency of 1099.9 b/s/Hz.
  • Masato Suzuki, Keisaku Yamane, Moritsugu Sakamoto, Kazuhiko Oka, Yasunori Toda, Ryuji Morita
    OPTICS EXPRESS 26 3 2584 - 2598 2018年02月 [査読有り][通常論文]
     
    We proposed and constructed a system to realize broadband generation of arbitrary axisymmetrically polarized (AP) pulses with spatial complex amplitude modulation. This system employs the combination of a spatial light modulator in the 4-f configuration (4-f SLM), and a space variant wave plate as a common path interferometer. The 4-f SLM and the common path interferometer offer compensation for spatial dispersion with respect to wavelength and stability to perturbation, respectively. We experimentally demonstrated the various AP pulses generation by applying modulations of fundamental and higher-order Laguerre-Gauss modes, whose radial indices were, respectively, p = 0 and 1, with high purity, which showed that we were able to generate arbitral AP pulses with spatial complex amplitude modulation. This technique is expected to be applied in both classical and quantum communications with higher-order modes. (c) 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
  • Yoshiaki Tamura, Hirotaka Sakuma, Keisei Morita, Masato Suzuki, Yoshinori Yamamoto, Kensaku Shimada, Yuya Honma, Kazuyuki Sohma, Takashi Fujii, Takemi Hasegawa
    JOURNAL OF LIGHTWAVE TECHNOLOGY 36 1 44 - 49 2018年01月 [査読有り][通常論文]
     
    We achieved the lowest-ever transmission losses of 0.1419 dB/km at 1560nm wavelength and 0.1424 dB/km at 1550nm in a Ge-free silica-core optical fiber. It was an improvement by 4 mdB/km from the previous record realized in 2015. The Ge-free silica core included fluorine co-doping, which helps to reduce disorder in the microscopic glass network structure that causes Rayleigh scattering loss without a significant increase in waveguide imperfection loss. A two-layered polymer coating with an inner layer having lower elastic modulus than before also contributed to the ultralow loss without influence of microbending loss increase even with an enlarged effective area of 147 mu m(2). The present fiber with ultralow loss and a large effective area benefits an ultralong haul optical transmission system including transoceanic submarine cable systems. We estimate system performance based on the fiber figure of merit theory that the present fiber enables a 0.10 bit/s/Hz increase in spectral efficiency or 7% reduction in the number of repeaters, compared to the previous record-loss fiber.
  • Lowest-Ever 0.1419-dB/km Loss Optical Fiber
    Yoshiaki Tamura, Hirotaka Sakuma, Keisei Morita, Masato Suzuki, Yoshinori Yamamoto, Kensaku Shimada, Yuya Honma, Kazuyuki Sohma, Takashi Fujii, Takemi Hasegawa
    2017 OPTICAL FIBER COMMUNICATIONS CONFERENCE AND EXHIBITION (OFC) 2017年 [査読有り][通常論文]
     
    Lowest-ever 0.1419-dB/km loss at 1560-nm wavelength was realized in a silica-core fiber with 1290-degrees C low fictive temperature, 147-mu m(2) large effective area and low microbending loss due to soft primary coating.
  • Low-loss Splice of Large Effective Area Fiber Using Fluorine-doped Cladding Standard Effective Area Fiber
    Masato Suzuki, Yoshiaki Tamura, Yoshinori Yamamoto, Takemi Hasegawa
    2017 OPTICAL FIBER COMMUNICATIONS CONFERENCE AND EXHIBITION (OFC) 2017年 [査読有り][通常論文]
     
    Ultra-low dissimilar splice loss of 0.08dB between A(eff)-enlarged fiber (148 mu m(2)) and standard A(eff) fiber (83 mu m(2)) was realized, by applying a ring core profile to A(eff)-enlarged fiber and fluorine doped cladding to standard A(eff) fiber.
  • Kyohhei Shigematsu, Masato Suzuki, Keisaku Yamane, Ryuji Morita, Yasunori Toda
    APPLIED PHYSICS EXPRESS 9 12 2016年12月 [査読有り][通常論文]
     
    By using radially polarized pulses for excitation in degenerate four-wave mixing (DFWM) spectroscopy, we realize highly sensitive snap-shot measurement of optical anisotropies in semiconductor films. Because the radially polarized pulses exhibit spatially varying linear polarizations, the optical anisotropies in samples can be evaluated from the spatial distributions of DFWM signals without rotating the polarization of the excitation pulses. We measure the excitons in GaN layers and evaluate the energies of uniaxial strain and the spin-exchange interaction constant. Our results prove both the accuracy and sensitivity of the snap-shot measurement. (C) 2016 The Japan Society of Applied Physics
  • Masato Suzuki, Keisaku Yamane, Kazuhiko Oka, Yasunori Toda, Ryuji Morita
    Physical Review A - Atomic, Molecular, and Optical Physics 94 2016年10月26日 [査読無し][通常論文]
     
    © 2016 American Physical Society.We derived the Berry connection of vector vortex states (VVSs) from the "true" Hamiltonian obtained through the Maxwell-Schrödinger equation for an inhomogeneous anisotropic (IA) medium, and we experimentally demonstrated measurement of the corresponding Pancharatnam-Berry (PB) geometrical phase of VVSs. The PB phase (PBP) of VVSs can be divided into two phases: homogeneous and inhomogeneous PBPs. Homogeneous and inhomogeneous PBPs are related to the conventional PBP and the spatially dependent geometric phase given by an IA medium such as a polarization converter, respectively. We theoretically detected that inhomogeneous PBP accumulation originates from the gauge dependence of the index of the hybrid-order Poincaré sphere, which provides an alternate method for understanding optical spin-orbital angular momentum conversion. The homogeneous PBP, which is explicitly observed, has implications for quantum-state manipulation and information processing.
  • Masato Suzuki, Keisaku Yamane, Kazuhiko Oka, Yasunori Toda, Ryuji Morita
    PHYSICAL REVIEW A 94 4 2016年10月 [査読有り][通常論文]
     
    We derived the Berry connection of vector vortex states (VVSs) from the "true" Hamiltonian obtained through the Maxwell-Schrodinger equation for an inhomogeneous anisotropic (IA) medium, and we experimentally demonstrated measurement of the corresponding Pancharatnam-Berry (PB) geometrical phase of VVSs. The PB phase (PBP) of VVSs can be divided into two phases: homogeneous and inhomogeneous PBPs. Homogeneous and inhomogeneous PBPs are related to the conventional PBP and the spatially dependent geometric phase given by an IA medium such as a polarization converter, respectively. We theoretically detected that inhomogeneous PBP accumulation originates from the gauge dependence of the index of the hybrid-order Poincare sphere, which provides an alternate method for understanding optical spin-orbital angular momentum conversion. The homogeneous PBP, which is explicitly observed, has implications for quantum-statemanipulation and information processing.
  • Masato Suzuki, Keisaku Yamane, Kazuhiko Oka, Yasunori Toda, Ryuji Morita
    SCIENTIFIC REPORTS 5 2015年12月 [査読有り][通常論文]
     
    Cylindrically polarized (CP) modes are laser beam modes which have rotational symmetry of the polarization distribution around the beam axis. Considerable attention has been paid to CP modes for their various applications. In this paper, by using the extended Stokes parameters and the degree of polarization defined for the spatial distribution (DOP-SD), we fully-quantitatively characterize the spectrally-resolved polarization states of arbitrary CP (axisymmetrically polarized and higher-order cylindrically polarized) broadband pulses generated by coherent beam combining. All the generated pulse states were fully-quantitatively analyzed for the first time and proved to have high symmetry (DOP-SD greater than or similar to 0.95) and low spectral dependence of polarization states. Moreover, we show the DOP-SD, which cannot be defined by the conventional higher-order and hybrid Stokes parameters, enables us to make a quantitative evaluation of small degradation of rotational symmetry of polarization distribution. This quantitative characterization with high precision is significant for applications of precise material processing, quantum information processing, magneto-optical storage and nonlinear spectroscopic polarimetry.
  • Masato Suzuki, Keisaku Yamane, Kazuhiko Oka, Yasunori Toda, Ryuji Morita
    OPTICAL REVIEW 22 1 179 - 183 2015年02月 [査読有り][通常論文]
     
    The extended Stokes parameters for arbitrary cylindrically polarized beams are newly introduced to evaluate their quality. A set of the parameters, expressing a cylindrically polarized state, permits the definition of the degree of polarization that indicates the purity of the spatial symmetry of polarization of a light beam. In addition, the Pancharatnam-Berry phase related to the cylindrically polarized states is described by the new Stokes parameters.
  • Quantitative characterization of polarization states of axisymmetrically polarized pulses generated by coherent beam combining
    Masato Suzuki, Keisaku Yamane, Kazuhiko Oka, Yasunori Toda, Ryuji Morita
    2015 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) 2015年 [査読有り][通常論文]
     
    By using the extended Stokes parameters and the degree of polarization defined for the spatial distribution (DOP-SD), we fully quantitatively characterize the polarization states of arbitrary (DOP-SD> 0.96) axisymmetrically-polarized femtosecond pulses generated by coherent beam combining. (C) 2014 Optical Society of America
  • Masato Suzuki, Keisaku Yamane, Kazuhiko Oka, Yasunori Toda, Ryuji Morita
    OPTICS EXPRESS 22 14 16903 - 16915 2014年07月 [査読有り][通常論文]
     
    Nonlinear propagation of focused axisymmetrically-polarized ultrashort optical pulses along the optic axis in a uniaxial crystal is investigated experimentally and theoretically. The energy transfer between an azimuthally-polarized pulse and a radially-polarized pulse is observed. To analyze the nonlinear propagation, a general paraxial equation with a third-order nonlinearity for axisymmetrically-polarized pulses in a uniaxial crystal is derived and the extended Stokes parameters (ESPs) based on cylindrical coordinates are newly-introduced. The simulation results by using this equation, providing the calculated ESPs, well explain our experimental observations: 1) the energy transfer is attributed to the four-wave-mixing effect, reflecting the overlapping between the axisymmetrically polarized modes, 2) the variations of the polarization defined from the ESPs are clarified to be affected by the self-and the cross-phase modulations, which make the effective propagation length long or short. (C) 2014 Optical Society of America
  • Generation of ultra-broadband pulses with axially-symmetric polarization based on coherent beam combining of optical vortices
    Keisaku Yamane, Yasuyuki Shioda, Masato Suzuki, Yasunori Toda, Ryuji Morita
    2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) 2014年 [査読有り][通常論文]
     
    We demonstrated the generation of ultra-broadband optical pulses with axially-symmetric polarization, on the basis of a coherent beam combining technique. The high polarization purity (similar to 95 %) ranging from 750 to 880 nm was obtained. (C) 2014 Optical Society of America
  • Nonlinear Coupling Between Radially- And Azimuthally-Polarized Modes of Ultrashort Optical Pulses in an Anisotropic Crystal
    Masato Suzuki, Keisaku Yamane, Yasunori Toda, Ryuji Morita
    2013 CONFERENCE ON LASERS AND ELECTRO-OPTICS PACIFIC RIM (CLEO-PR) 2013年 [査読有り][通常論文]
     
    We investigate nonlinear propagation of ultrashort optical pulses with radially- and azimuthally-polarized modes in a uniaxial crystal. The energy exchange between the modes, ascribed to nonlinear four-wave-mixing effect with Gouy-phase shifts, is discussed.
  • Nonlinear Conversion between Ultrashort Radially- and Azimuthally-Polarized Pulses in an Anisotropic Media
    Masato Suzuki, Keisaku Yamane, Yasunori Toda, Ryuji Morita
    2013 CONFERENCE ON LASERS AND ELECTRO-OPTICS EUROPE AND INTERNATIONAL QUANTUM ELECTRONICS CONFERENCE (CLEO EUROPE/IQEC) 2013年 [査読有り][通常論文]

その他活動・業績

受賞

  • 2017年12月 2017年 光通信システム研究会 論文賞
  • 2013年07月 Best Student Awards of CLEO Pacific Rim
  • 2011年03月 北海道大学工学部第6回William Wheeler Prize
  • 2011年02月 北海道大学教育GP卒論ポスター発表会最優秀賞
  • 2008年06月 北海道大学新渡戸賞

共同研究・競争的資金等の研究課題

  • 非線型光学効果による超短トポロジカル光波の全角運動量超高速制御
    日本学術振興会:科学研究費助成事業 特別研究員奨励費
    研究期間 : 2015年04月 -2017年03月 
    代表者 : 鈴木 雅人
     
    本研究では、超短トポロジカル光波の全角運動量を一軸性結晶の非線型光学効果を通じて超高速制御し、超短トポロジカル光波を用いた光多重通信への有用性を示すことを目指している。そのために、全角運動量を有する超短トポロジカル光波が一軸性結晶内で非線型伝播する際の全角運動量分布の変化について明らかする。平成27年度は、全角運動量を有する超短トポロジカル光波が一軸性結晶内で非線型伝播する際の全角運動量分布の変化を実験的に明らかにする研究目標を達成するため、1.全角運動量を有する超短トポロジカル光波生成系の構築、2.偏光分布(スピン角運動量分布)測定と軌道角運動量分布測定を融合した、超短トポロジカル光波の全角運動量分布精密測定系の構築を行った。 1に関しては、円筒対称偏光分布を有する広帯域光パルスをコヒーレント結合系で生成した。この広帯域光パルスは申請者が提案している拡張ストークスパラメータ・拡張偏光度と呼ばれる基準を通じて完全定量的に評価された。生成した円筒対称偏光分布を有する広帯域光パルスは、適切な分散補償をコヒーレント結合系の前で施すことにより、超短トポロジカル光波に成りえるため、全角運動量を有する超短トポロジカル光波生成系の構築がほぼ完成している状態である。 2に関しては、偏光分布を測定するために一般的に用いられる回転位相子法と、軌道角運動量分布測定を行うために申請者が所属する研究グループが提案している干渉を用いた光電場再生法を組み合わせ、全角運動量分布精密測定系の構築を行った。実験による検証の結果、エネルギー比にして数%程度の他モード混入が見分けられることが分かった。


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