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Tetsuya Mizumoto - One of the best experts on this subject based on the ideXlab platform.

  • integrated widely tunable broadband Optical Isolator in silicon photonics
    European Conference on Optical Communication, 2017
    Co-Authors: Paolo Pintus, Yuya Shoji, Tetsuya Mizumoto, Duanni Huang, M J Kennedy, Paul A Morton, John E Bowers
    Abstract:

    We experimentally demonstrate a Mach-Zehnder based Optical Isolator in silicon photonics. A maximum isolation ratio larger than 30dB is measured, while more than 18dB of isolation is guaranteed over 15nm-wide bandwidth. Finally, the isolation wavelength is effectively tuned over 72nm.

  • amorphous si waveguide on a garnet magneto Optical Isolator with a te mode nonreciprocal phase shift
    Optics Express, 2017
    Co-Authors: Eiichi Ishida, Yuya Shoji, Tetsuya Mizumoto, Hideki Yokoi, Kengo Miura, Nobuhiko Nishiyama, Shigehisa Arai
    Abstract:

    We fabricated a magneto-Optical (MO) Isolator with a TE mode nonreciprocal phase shift. The Isolator is based on a Mach-Zehnder interferometer composed of 3-dB directional couplers, a reciprocal phase shifter, and a nonreciprocal phase shifter. To realize TE mode operation in the Optical Isolator, we designed a novel waveguide structure composed of a hydrogenated amorphous silicon waveguide with an asymmetric MO garnet lateral clad on a garnet substrate. The Isolator operation is successfully demonstrated in a fabricated device showing the different transmittances between forward and backward directions. The maximum isolation of the fabricated Isolator is 17.9 dB at a wavelength of 1561 nm for the TE mode.

  • Silicon Waveguide Optical Isolator Operating for TE Mode Input Light
    IEEE Journal of Selected Topics in Quantum Electronics, 2016
    Co-Authors: Yuya Shoji, Akihiro Fujie, Tetsuya Mizumoto
    Abstract:

    A waveguide Optical Isolator with a nonreciprocal phase shift is promising for obtaining high-Optical isolation owing to its single-polarization operation. A typical configuration enables operation for only the TM mode input light. A silicon waveguide polarization rotator with asymmetric two parallel waveguides is implemented with the silicon waveguide Optical Isolator for operation with the TE mode input light. Maximal isolation of 26.7 dB at the wavelength of 1553 nm is demonstrated experimentally.

  • athermal operation of a waveguide Optical Isolator based on canceling phase deviations in a mach zehnder interferometer
    Journal of Lightwave Technology, 2016
    Co-Authors: Kotoko Furuya, Yuya Shoji, Keita Kato, Takaya Nemoto, Tetsuya Mizumoto
    Abstract:

    Optical Isolators play unique roles in photonic circuits. We have developed an Optical Isolator with silicon waveguides, based on a Mach–Zehnder interferometer. The device characteristics were temperature dependent. We investigated the temperature dependence of the refractive index ( ${\rm d}n/{\rm d}T$ ) and the magneto-Optical coefficient ( ${\rm d}\theta _f /{\rm d}T$ ) of a magneto-Optical garnet Ce:YIG, and estimated these as $9.1 \times 10^{-5}$ K−1 and 44 ${\rm }^\circ \cdot {\rm cm}^{- 1} \cdot {\rm K}^{- 1} $ , respectively. We discuss the design of an athermal silicon waveguide Optical Isolator, in which the temperature dependences of the magneto-Optical effect and refractive indices are canceled in the backward direction. The high Optical isolation, greater than 20 dB, is demonstrated for temperature in the 20–60 °C range.

  • Demonstration of an athermal waveguide Optical Isolator on silicon platform
    2015 European Conference on Optical Communication (ECOC), 2015
    Co-Authors: Kotoko Furuya, Yuya Shoji, Keita Kato, Tetsuya Mizumoto
    Abstract:

    We demonstrate an athermal waveguide Optical Isolator on a silicon platform where the temperature dependences of the magneto-optic effect and refractive indices were cancelled for the backward direction. The isolation ratio over 20 dB was maintained at 20–60 °C.

Yuya Shoji - One of the best experts on this subject based on the ideXlab platform.

  • integrated widely tunable broadband Optical Isolator in silicon photonics
    European Conference on Optical Communication, 2017
    Co-Authors: Paolo Pintus, Yuya Shoji, Tetsuya Mizumoto, Duanni Huang, M J Kennedy, Paul A Morton, John E Bowers
    Abstract:

    We experimentally demonstrate a Mach-Zehnder based Optical Isolator in silicon photonics. A maximum isolation ratio larger than 30dB is measured, while more than 18dB of isolation is guaranteed over 15nm-wide bandwidth. Finally, the isolation wavelength is effectively tuned over 72nm.

  • amorphous si waveguide on a garnet magneto Optical Isolator with a te mode nonreciprocal phase shift
    Optics Express, 2017
    Co-Authors: Eiichi Ishida, Yuya Shoji, Tetsuya Mizumoto, Hideki Yokoi, Kengo Miura, Nobuhiko Nishiyama, Shigehisa Arai
    Abstract:

    We fabricated a magneto-Optical (MO) Isolator with a TE mode nonreciprocal phase shift. The Isolator is based on a Mach-Zehnder interferometer composed of 3-dB directional couplers, a reciprocal phase shifter, and a nonreciprocal phase shifter. To realize TE mode operation in the Optical Isolator, we designed a novel waveguide structure composed of a hydrogenated amorphous silicon waveguide with an asymmetric MO garnet lateral clad on a garnet substrate. The Isolator operation is successfully demonstrated in a fabricated device showing the different transmittances between forward and backward directions. The maximum isolation of the fabricated Isolator is 17.9 dB at a wavelength of 1561 nm for the TE mode.

  • Silicon Waveguide Optical Isolator Operating for TE Mode Input Light
    IEEE Journal of Selected Topics in Quantum Electronics, 2016
    Co-Authors: Yuya Shoji, Akihiro Fujie, Tetsuya Mizumoto
    Abstract:

    A waveguide Optical Isolator with a nonreciprocal phase shift is promising for obtaining high-Optical isolation owing to its single-polarization operation. A typical configuration enables operation for only the TM mode input light. A silicon waveguide polarization rotator with asymmetric two parallel waveguides is implemented with the silicon waveguide Optical Isolator for operation with the TE mode input light. Maximal isolation of 26.7 dB at the wavelength of 1553 nm is demonstrated experimentally.

  • athermal operation of a waveguide Optical Isolator based on canceling phase deviations in a mach zehnder interferometer
    Journal of Lightwave Technology, 2016
    Co-Authors: Kotoko Furuya, Yuya Shoji, Keita Kato, Takaya Nemoto, Tetsuya Mizumoto
    Abstract:

    Optical Isolators play unique roles in photonic circuits. We have developed an Optical Isolator with silicon waveguides, based on a Mach–Zehnder interferometer. The device characteristics were temperature dependent. We investigated the temperature dependence of the refractive index ( ${\rm d}n/{\rm d}T$ ) and the magneto-Optical coefficient ( ${\rm d}\theta _f /{\rm d}T$ ) of a magneto-Optical garnet Ce:YIG, and estimated these as $9.1 \times 10^{-5}$ K−1 and 44 ${\rm }^\circ \cdot {\rm cm}^{- 1} \cdot {\rm K}^{- 1} $ , respectively. We discuss the design of an athermal silicon waveguide Optical Isolator, in which the temperature dependences of the magneto-Optical effect and refractive indices are canceled in the backward direction. The high Optical isolation, greater than 20 dB, is demonstrated for temperature in the 20–60 °C range.

  • Demonstration of an athermal waveguide Optical Isolator on silicon platform
    2015 European Conference on Optical Communication (ECOC), 2015
    Co-Authors: Kotoko Furuya, Yuya Shoji, Keita Kato, Tetsuya Mizumoto
    Abstract:

    We demonstrate an athermal waveguide Optical Isolator on a silicon platform where the temperature dependences of the magneto-optic effect and refractive indices were cancelled for the backward direction. The isolation ratio over 20 dB was maintained at 20–60 °C.

Hideki Yokoi - One of the best experts on this subject based on the ideXlab platform.

  • amorphous si waveguide on a garnet magneto Optical Isolator with a te mode nonreciprocal phase shift
    Optics Express, 2017
    Co-Authors: Eiichi Ishida, Yuya Shoji, Tetsuya Mizumoto, Hideki Yokoi, Kengo Miura, Nobuhiko Nishiyama, Shigehisa Arai
    Abstract:

    We fabricated a magneto-Optical (MO) Isolator with a TE mode nonreciprocal phase shift. The Isolator is based on a Mach-Zehnder interferometer composed of 3-dB directional couplers, a reciprocal phase shifter, and a nonreciprocal phase shifter. To realize TE mode operation in the Optical Isolator, we designed a novel waveguide structure composed of a hydrogenated amorphous silicon waveguide with an asymmetric MO garnet lateral clad on a garnet substrate. The Isolator operation is successfully demonstrated in a fabricated device showing the different transmittances between forward and backward directions. The maximum isolation of the fabricated Isolator is 17.9 dB at a wavelength of 1561 nm for the TE mode.

  • Integrating Laser Diode and Optical Isolator by Photosensitive Adhesive Bonding
    ECS Transactions, 2013
    Co-Authors: Hideki Yokoi, Norihiko Ichishima, Isamu Myouenzono
    Abstract:

    Figure 1 shows a laser diode integrated with an Optical Isolator by photosensitive adhesive bonding. The Optical Isolator employing a nonreciprocal phase shift has an a-Si guiding layer deposited on a CeY2Fe5O12 (Ce:YIG) cladding layer (1). The nonreciprocal phase shift occurs in TM modes that travel in magneto-optic waveguides in which magnetization is aligned transverse to the light propagation direction in the film plane. An Optical interferometer is comprised of two multimode interference (MMI) couplers, nonreciprocal phase shifters in two arms and a reciprocal phase shifter in one of the arms. The reciprocal phase shift is obtained by an Optical path difference between the two arms. An external magnetic field is applied to two arms in the interferometer in order to achieve a push-pull nonreciprocal phase shift. The nonreciprocal phase shift was calculated for a magneto-optic waveguide with an air/a-Si/Ce:YIG structure. Faraday rotation coefficient of Ce:YIG is approximately -7.85×10 rad/m at 1.55 μm (2). When the a-Si guiding layer thickness was 190 nm, a required propagation distance for the nonreciprocal phase shifter was approximately 190 μm. The MMI coupler and the reciprocal phase shifter were also designed at 1.55 μm. The total device length for an Isolator operation was approximately 300 μm. When the laser diode is integrated with the Optical Isolator by photosensitive adhesive bonding, a gap between a top layer of the laser diode and the Optical Isolator is an important parameter for an output coupling efficiency. Figure 2 shows the coupling efficiency from an active layer of the laser diode to a guiding layer of the Optical Isolator. The gap should be less than 50 nm to obtain efficient coupling. Photosensitive adhesive bonding between a laser diode and an Optical Isolator was studied. As a preliminary experiment, adhesive bonding between Gd3Ga5O12 (GGG) and SiO2 was attempted by use of photosensitive adhesive (TOKYO OHKA KOGYO CO., LTD.). The adhesive bonding between GGG and SiO2 was successfully achieved with the heat treatment at 160°C.

  • Adhesive bonding for integrating laser diode and Optical Isolator
    2012 3rd IEEE International Workshop on Low Temperature Bonding for 3D Integration, 2012
    Co-Authors: Hideki Yokoi, Isamu Myouenzono, Norihiko Ichishima
    Abstract:

    Integrating a laser diode and an Optical Isolator with a Si guiding layer was investigated by means of adhesive bonding.

  • Design of Optical Isolator with Sputter-Deposited Si Layer Employing Nonreciprocal Radiation-Mode Conversion
    Japanese Journal of Applied Physics, 2011
    Co-Authors: Hideki Yokoi, Kazuya Yamaguchi, Yuki Uchiumi
    Abstract:

    An Optical Isolator with a Si guiding layer that employs a nonreciprocal guided-radiation mode conversion is discussed. The Si guiding layer was sputter-deposited on a magnetic-garnet cladding layer. A magnetooptic waveguide in the Optical Isolator had an air/Si/magnetic-garnet structure. A nonreciprocal phase shift in the magnetooptic waveguide was calculated at a wavelength of 1.55 µm. The Optical Isolator employing the nonreciprocal guided-radiation mode conversion was designed for 1.55 µm.

  • Interferometric Optical Isolator with Air/Si/Magnetic-Garnet Waveguide Operated in Unidirectional Magnetic Field
    Japanese Journal of Applied Physics, 2010
    Co-Authors: Hideki Yokoi, Shun Igarashi, Yuki Uchiumi
    Abstract:

    An Optical Isolator with a TiO2/magnetic garnet waveguide obtained using a nonreciprocal phase shift was studied. The Optical Isolator can be operated in a unidirectional magnetic field owing to an interferometer with distinct layer structures.

Roel Baets - One of the best experts on this subject based on the ideXlab platform.

  • Ce:YIG/Silicon-on-Insulator waveguide Optical Isolator realized by adhesive bonding
    Optics Express, 2012
    Co-Authors: Samir Ghosh, S. Keyvavinia, Tetsuya Mizumoto, Gunther Roelkens, Roel Baets
    Abstract:

    A waveguide Optical Isolator realized by adhesive bonding of a garnet die, containing a Ce:YIG magneto-optic layer, on a silicon-on-insulator waveguide circuit is demonstrated. The die was bonded on top of an asymmetric Mach-Zehnder interferometer using a 100nm thick DVS-BCB adhesive bonding layer. A static magnetic field applied perpendicular to the light propagation direction results in a non-reciprocal phase shift for the fundamental quasi-TM mode in the hybrid waveguide geometry. A maximum Optical isolation of 25 dB is obtained.

  • ce yig silicon on insulator waveguide Optical Isolator realized by adhesive bonding
    Optics Express, 2012
    Co-Authors: Samir Ghosh, S. Keyvavinia, Tetsuya Mizumoto, Gunther Roelkens, Roel Baets
    Abstract:

    A waveguide Optical Isolator realized by adhesive bonding of a garnet die, containing a Ce:YIG magneto-optic layer, on a silicon-on-insulator waveguide circuit is demonstrated. The die was bonded on top of an asymmetric Mach-Zehnder interferometer using a 100nm thick DVS-BCB adhesive bonding layer. A static magnetic field applied perpendicular to the light propagation direction results in a non-reciprocal phase shift for the fundamental quasi-TM mode in the hybrid waveguide geometry. A maximum Optical isolation of 25 dB is obtained.

  • ce yig soi Optical Isolator realized by bcb bonding
    International Conference on Group IV Photonics, 2011
    Co-Authors: Samir Ghosh, Tetsuya Mizumoto, Gunther Roelkens, S. Keyvaninia, W Van Roy, Roel Baets
    Abstract:

    In this paper we demonstrate an Optical Isolator on a Silicon-on-Insulator waveguide platform realized by the adhesive bonding of Ce:YIG on top of a Mach-Zehnder interferometer. An Optical isolation of 25dB is experimentally obtained.

  • Ce:YIG/SOI Optical Isolator realized by BCB bonding
    8th IEEE International Conference on Group IV Photonics, 2011
    Co-Authors: Samir Ghosh, Tetsuya Mizumoto, Gunther Roelkens, S. Keyvaninia, Roel Baets
    Abstract:

    In this paper we demonstrate an Optical Isolator on a Silicon-on-Insulator waveguide platform realized by the adhesive bonding of Ce:YIG on top of a Mach-Zehnder interferometer. An Optical isolation of 25dB is experimentally obtained.

  • Amplifying Waveguide Optical Isolator With an Integrated Electromagnet
    IEEE Photonics Technology Letters, 2007
    Co-Authors: W. Van Parys, Roel Baets, D. Van Thourhout, Beatrice Dagens, Jean Decobert, O. Le Gouezigou, Dalila Make, Liesbet Lagae
    Abstract:

    We have demonstrated an amplifying waveguide Optical Isolator with an integrated electromagnet. This provides a solution to the generally poor magnetic remanence of this type of Isolator. The proof of principle is presented and optimization routes are discussed.

H Dotsch - One of the best experts on this subject based on the ideXlab platform.

  • polarization independent waveguide Optical Isolator based on nonreciprocal phase shift
    IEEE Photonics Technology Letters, 2000
    Co-Authors: J Fujita, Richard M. Osgood, M Levy, L Wilkens, H Dotsch
    Abstract:

    A polarization-independent waveguide Optical Isolator based on nonreciprocal interference is proposed. The design uses simultaneous TE and TM nonreciprocal phase shifts obtained from geometric asymmetry in horizontal and vertical axes of waveguide cross section along with opposing transverse and vertical magnetic fields in interferometer arms. A design to achieve such an Isolator is described. Both TE and TM nonreciprocal phase shifts comparable to the theoretical counterparts have also been experimentally observed from a single waveguide.

  • waveguide Optical Isolator based on mach zehnder interferometer
    Applied Physics Letters, 2000
    Co-Authors: J Fujita, Richard M. Osgood, M Levy, L Wilkens, H Dotsch
    Abstract:

    A waveguide Optical Isolator based on nonreciprocal interference is demonstrated. Ridge waveguides are fabricated in a Mach–Zehnder configuration on a single film of bismuth-, lutetium-, neodymium-iron garnet. With this design, no polarizers are required to achieve extinction in the backward propagation direction. This Isolator exhibits a 19 dB extinction ratio at λ=1.54 μm. A flat wavelength dependence, to within 2 dB, has been observed in the range between 1.49 and 1.57 μm.

  • analysis of polarization independent mach zehnder type integrated Optical Isolator
    Journal of Lightwave Technology, 1999
    Co-Authors: O Zhuromskyy, H Dotsch, Manfred Lohmeyer, N Bahlmann, P Hertel, A F Popkov
    Abstract:

    This paper proposes, for the first time, an integrated Optical Isolator independent of light polarization. A Mach-Zehnder interferometer (MZI) with two nonreciprocal phase shifters, one for transverse electric (TE) modes and another one for transverse magnetic (TM) modes can be adjusted so that it blocks the fundamental modes of the waveguides constituting the interferometer propagating in one direction and is transparent for the modes propagating in the opposite direction. If the interferometer branch waveguides are in single mode regime, the performance of the device will not depend on the polarization of incoming light. The nonreciprocal phase shifters can be realized on structures with magnetization tangential to the propagation direction. Three geometries of nonreciprocal phase shifters are discussed and tolerances are estimated.