The Experts below are selected from a list of 4080 Experts worldwide ranked by ideXlab platform

Toshihiko Baba - One of the best experts on this subject based on the ideXlab platform.

  • dipole mode photonic Crystal Point Defect laser on ingaasp inp
    Journal of Crystal Growth, 2006
    Co-Authors: Wanhua Zheng, Gang Ren, X.h. Cai, Liang Chen, Kengo Nozaki, X T, Toshihiko Baba
    Abstract:

    In this paper, we focus on the dipole mode of the two-dimensional (2D) photonic Crystal (PC) single Point Defect cavity (SPDC) lasers and we report the fabrication and characterization of 2D PC SPDC lasers with the structure of adjusted innermost air holes. The photonic band and cavity Q factors are simulated by means of plane wave expansion (PWE) and finite-difference time-domain (FDTD), respectively. In order to improve the optical confinement of the SPDC, the diameter of the innermost holes was adjusted. Different lasing performances are observed experimentally. The experimental results agree with the theoretical prediction very well.

  • Semiconductor Nanolasers and Photonic Molecules
    2006 International Conference on Transparent Optical Networks, 2006
    Co-Authors: Toshihiko Baba, Ken Nozaki, Satoru Ishii
    Abstract:

    This presentation shows the recent progress on photonic molecules (PMs) based on semiconductor micro/nanolasers. Microdisk cavities easily achieve the room temperature cw lasing by a whispering gallery mode. The splitting of bonding and antibonding modes and the miniband formation by the mode coupling are clearly observed in microdisk PMs. By using the nonuniform pumping, the bistable mode switching due to the saturable absorption and the nonlinear gain is also obtained. Photonic Crystal Point Defect nanocavities enable us to use simpler modes as original modes, i.e. s-orbital-like and p-orbital-like modes. PMs consisting of such nanocavities exhibit the sigma- and pi-couplings, which are very similar to chemical bonding states. Some of these coupled modes having a high Q are experimentally confirmed using the photonic Crystal slab

  • Dipole mode photonic Crystal Point Defect laser on InGaAsP/InP
    Journal of Crystal Growth, 2006
    Co-Authors: Wanhua Zheng, Gang Ren, X.h. Cai, Liang Chen, Kengo Nozaki, Toshihiko Baba
    Abstract:

    In this paper, we focus on the dipole mode of the two-dimensional (2D) photonic Crystal (PC) single Point Defect cavity (SPDC) lasers and we report the fabrication and characterization of 2D PC SPDC lasers with the structure of adjusted innermost air holes. The photonic band and cavity Q factors are simulated by means of plane wave expansion (PWE) and finite-difference time-domain (FDTD), respectively. In order to improve the optical confinement of the SPDC, the diameter of the innermost holes was adjusted. Different lasing performances are observed experimentally. The experimental results agree with the theoretical prediction very well.

  • observation of fast spontaneous emission decay in gainasp photonic Crystal Point Defect nanocavity at room temperature
    Applied Physics Letters, 2004
    Co-Authors: Toshihiko Baba, K. Inoshita, Kengo Nozaki, D Sano, Yusuke Kuroki, Fumio Koyama
    Abstract:

    The spontaneous emission decay in a photonic Crystal slab nanocavity with a GaInAsP quantum well active region was measured at room temperature. Even far below lasing threshold, the decay was much faster than that for the as-grown wafer. A consideration including the enhanced spontaneous emission rate by the Purcell effect, intraband relaxation of carriers, nonradiative surface recombination, spatial hole burning, and carrier diffusion enabled us to explain different decay lifetime between on- and off-resonant conditions and between different size cavities. As a result, >16-fold shorter spontaneous emission lifetime was estimated, which strongly suggests the existence of a large Purcell effect.

  • Carrier plasma shift in GaInAsP photonic Crystal Point Defect cavity
    Electronics Letters, 2003
    Co-Authors: Toshihiko Baba, M. Shiga, K. Inoshita, Fumio Koyama
    Abstract:

    A 1.43-µm-GaInAsP photonic Crystal slab with a Point Defect cavity and line Defect waveguides has been fabricated. A ∼1.5 µm-wavelength light is inserted into the waveguide and the cavity resonant spectrum observed. A 5.6 nm blue shift in the resonant peak arising from the carrier plasma effect by photopumping is also observed. These results will be applicable to all-optical switches and tunable devices.

Tetsuo Anada - One of the best experts on this subject based on the ideXlab platform.

  • 2d microwave metallic photonic Crystal Point Defect cavity resonator
    Microwave and Optical Technology Letters, 2017
    Co-Authors: Chenglong Xie, Chun-ping Chen, Tetsuo Anada
    Abstract:

    Novel microwave high-Q Point-Defect-cavity (PDC) resonators based on metallic photonic Crystals (M-PhCs) are experimentally studied. After the illustration of the band structure of M-PhCs, the first two resonant modes of a PDC are computed by supper-cell methods. The results show that the Q-value of M-PhC PDCs is almost the same as that of the traditional waveguide cavity resonators. Moreover, the PDC is then fabricated and experimentally measured. The measured resonant frequencies and Q-factors are compared with the calculated ones to validate our computation and show the property of the proposed PDC.

  • 2D microwave metallic photonic Crystal Point‐Defect‐cavity resonator
    Microwave and Optical Technology Letters, 2017
    Co-Authors: Chenglong Xie, Chun-ping Chen, Tetsuo Anada
    Abstract:

    Novel microwave high-Q Point-Defect-cavity (PDC) resonators based on metallic photonic Crystals (M-PhCs) are experimentally studied. After the illustration of the band structure of M-PhCs, the first two resonant modes of a PDC are computed by supper-cell methods. The results show that the Q-value of M-PhC PDCs is almost the same as that of the traditional waveguide cavity resonators. Moreover, the PDC is then fabricated and experimentally measured. The measured resonant frequencies and Q-factors are compared with the calculated ones to validate our computation and show the property of the proposed PDC.

  • Design of a novel type of narrow band BPFs using high-Q M-PhC resonators
    2017 47th European Microwave Conference (EuMC), 2017
    Co-Authors: Chen-ping Chen, Tetsuo Anada, Shun Kikawa, Daisuke Tetsuda, Shigeki Takeda
    Abstract:

    This paper presents a design of a novel class of high-performance bandpass filters using various types of metallic-photonic-Crystal Point-Defect resonators (M-PhC PDRs). After a brief discussion on the bandgap of PhC structure and resonant modes of M-PhC PDRs, two new filters are designed using proposed M-PhC PDRs. Firstly, a novel trisection filter composed of M-PhC PDRs with hexagonal-lattice is designed at the first time. To realize attenuation pole, a new coupling window is proposed/introduced to realize negative coupling. The coaxial-probe-excitation is applied at ports, while the filter is synthesized in terms of coupling matrix scheme. Then, a novel planar-PhC-filter consisting of M-PhC PDRs and microstrip-line-excitation is synthesized and experimentally realized to validate the possibility of seamless integration of two types of transmission lines. The performances of designed filters are confirmed.

  • computation and measurement of microwave metallic photonic Crystal Point Defect cavity
    Asia-Pacific Microwave Conference, 2016
    Co-Authors: Chun-ping Chen, Tetsuo Anada, Kazuki Kanazawa, Takaharu Hiraoka, Shigeki Takeda
    Abstract:

    By changing the radius of the rod in the center of a Point-Defect-cavity (PDC) based on metallic photonic Crystals (M-PhCs), a novel type of microwave cavity with an adjustable resonant-frequency is proposed and studied. After the illustration of the band structure of M-PhCs, the first 3 resonant modes of the Point-Defect-cavity (PDC) are computed by supper-cell methods, whereas the relation between the convergence of calculated resonant frequencies of PDC and the number of rods considered in a single cell is focused. Moreover, a PDC is then fabricated and experimentally measured. The measured resonant frequencies and Q-factors, reported at the first time, are compared to the calculated ones to validate our computation and show its properties. Finally, a PDC-based filter is designed to show its potential applications in microwave regime.

  • Proposal and Design of metallic-photonic-Crystal-resonator filters with attenuation poles using coupling matrix method
    2016 Progress in Electromagnetic Research Symposium (PIERS), 2016
    Co-Authors: Chun-ping Chen, Tetsuo Anada, Shigeki Takeda
    Abstract:

    This paper proposes a design of a novel class of high-selectivity bandpass filters (BPFs) composed of multistage of metallic-photonic-Crystal Point-Defect resonators. The proposed filters are designed/synthesized using the coupling matrix scheme. The resonant frequency of each resonator is controlled by the radius of the centrally-loaded metal rod, while the coupling between the adjacent resonators is tuned by the coupling windows. After the computation of band structure of the square-lattice metallic-photonic-Crystal and mode-chart of Point-Defect resonators, three example filters with 2-poles-1-transmission-zero (TZ), 3-poles-1-TZ and 4-poles-2TZs are then designed to validate the proposed filter structures and the corresponding design/synthesis scheme.

Chun-ping Chen - One of the best experts on this subject based on the ideXlab platform.

  • 2d microwave metallic photonic Crystal Point Defect cavity resonator
    Microwave and Optical Technology Letters, 2017
    Co-Authors: Chenglong Xie, Chun-ping Chen, Tetsuo Anada
    Abstract:

    Novel microwave high-Q Point-Defect-cavity (PDC) resonators based on metallic photonic Crystals (M-PhCs) are experimentally studied. After the illustration of the band structure of M-PhCs, the first two resonant modes of a PDC are computed by supper-cell methods. The results show that the Q-value of M-PhC PDCs is almost the same as that of the traditional waveguide cavity resonators. Moreover, the PDC is then fabricated and experimentally measured. The measured resonant frequencies and Q-factors are compared with the calculated ones to validate our computation and show the property of the proposed PDC.

  • 2D microwave metallic photonic Crystal Point‐Defect‐cavity resonator
    Microwave and Optical Technology Letters, 2017
    Co-Authors: Chenglong Xie, Chun-ping Chen, Tetsuo Anada
    Abstract:

    Novel microwave high-Q Point-Defect-cavity (PDC) resonators based on metallic photonic Crystals (M-PhCs) are experimentally studied. After the illustration of the band structure of M-PhCs, the first two resonant modes of a PDC are computed by supper-cell methods. The results show that the Q-value of M-PhC PDCs is almost the same as that of the traditional waveguide cavity resonators. Moreover, the PDC is then fabricated and experimentally measured. The measured resonant frequencies and Q-factors are compared with the calculated ones to validate our computation and show the property of the proposed PDC.

  • computation and measurement of microwave metallic photonic Crystal Point Defect cavity
    Asia-Pacific Microwave Conference, 2016
    Co-Authors: Chun-ping Chen, Tetsuo Anada, Kazuki Kanazawa, Takaharu Hiraoka, Shigeki Takeda
    Abstract:

    By changing the radius of the rod in the center of a Point-Defect-cavity (PDC) based on metallic photonic Crystals (M-PhCs), a novel type of microwave cavity with an adjustable resonant-frequency is proposed and studied. After the illustration of the band structure of M-PhCs, the first 3 resonant modes of the Point-Defect-cavity (PDC) are computed by supper-cell methods, whereas the relation between the convergence of calculated resonant frequencies of PDC and the number of rods considered in a single cell is focused. Moreover, a PDC is then fabricated and experimentally measured. The measured resonant frequencies and Q-factors, reported at the first time, are compared to the calculated ones to validate our computation and show its properties. Finally, a PDC-based filter is designed to show its potential applications in microwave regime.

  • Proposal and Design of metallic-photonic-Crystal-resonator filters with attenuation poles using coupling matrix method
    2016 Progress in Electromagnetic Research Symposium (PIERS), 2016
    Co-Authors: Chun-ping Chen, Tetsuo Anada, Shigeki Takeda
    Abstract:

    This paper proposes a design of a novel class of high-selectivity bandpass filters (BPFs) composed of multistage of metallic-photonic-Crystal Point-Defect resonators. The proposed filters are designed/synthesized using the coupling matrix scheme. The resonant frequency of each resonator is controlled by the radius of the centrally-loaded metal rod, while the coupling between the adjacent resonators is tuned by the coupling windows. After the computation of band structure of the square-lattice metallic-photonic-Crystal and mode-chart of Point-Defect resonators, three example filters with 2-poles-1-transmission-zero (TZ), 3-poles-1-TZ and 4-poles-2TZs are then designed to validate the proposed filter structures and the corresponding design/synthesis scheme.

  • ic Bandpass Filter using Higher-Order Modes ofPhotonic Crystal Point Defect Cavity for Sub- Terahertz Bands
    2015
    Co-Authors: Chun-ping Chen, Tetsuo Anada, Shigeki Takeda, S. Greedy, Trevor M. Benson
    Abstract:

    In this paper, a novel compact 2D photonic crys­ tal bandpass resonant filter is proposed and designed on the ba­ sis of coupling matrix theory between the waveguide and Point Defect resonators with perturbing dielectric posts. The coupling matrix concept offers an accurate method for a direct synthesis of narrow-band filters and provides initial estimate of structure parameters for optimization design of PhC bandpass filters. By fine adjusting the structure parameters such as radius of the coupling rod, dielectric rod, and perturbing rod, the filter char­ acteristics are studied by using the finite difference time domain method.

Fumio Koyama - One of the best experts on this subject based on the ideXlab platform.

  • observation of fast spontaneous emission decay in gainasp photonic Crystal Point Defect nanocavity at room temperature
    Applied Physics Letters, 2004
    Co-Authors: Toshihiko Baba, K. Inoshita, Kengo Nozaki, D Sano, Yusuke Kuroki, Fumio Koyama
    Abstract:

    The spontaneous emission decay in a photonic Crystal slab nanocavity with a GaInAsP quantum well active region was measured at room temperature. Even far below lasing threshold, the decay was much faster than that for the as-grown wafer. A consideration including the enhanced spontaneous emission rate by the Purcell effect, intraband relaxation of carriers, nonradiative surface recombination, spatial hole burning, and carrier diffusion enabled us to explain different decay lifetime between on- and off-resonant conditions and between different size cavities. As a result, >16-fold shorter spontaneous emission lifetime was estimated, which strongly suggests the existence of a large Purcell effect.

  • Carrier plasma shift in GaInAsP photonic Crystal Point Defect cavity
    Electronics Letters, 2003
    Co-Authors: Toshihiko Baba, M. Shiga, K. Inoshita, Fumio Koyama
    Abstract:

    A 1.43-µm-GaInAsP photonic Crystal slab with a Point Defect cavity and line Defect waveguides has been fabricated. A ∼1.5 µm-wavelength light is inserted into the waveguide and the cavity resonant spectrum observed. A 5.6 nm blue shift in the resonant peak arising from the carrier plasma effect by photopumping is also observed. These results will be applicable to all-optical switches and tunable devices.

Kengo Nozaki - One of the best experts on this subject based on the ideXlab platform.

  • dipole mode photonic Crystal Point Defect laser on ingaasp inp
    Journal of Crystal Growth, 2006
    Co-Authors: Wanhua Zheng, Gang Ren, X.h. Cai, Liang Chen, Kengo Nozaki, X T, Toshihiko Baba
    Abstract:

    In this paper, we focus on the dipole mode of the two-dimensional (2D) photonic Crystal (PC) single Point Defect cavity (SPDC) lasers and we report the fabrication and characterization of 2D PC SPDC lasers with the structure of adjusted innermost air holes. The photonic band and cavity Q factors are simulated by means of plane wave expansion (PWE) and finite-difference time-domain (FDTD), respectively. In order to improve the optical confinement of the SPDC, the diameter of the innermost holes was adjusted. Different lasing performances are observed experimentally. The experimental results agree with the theoretical prediction very well.

  • Dipole mode photonic Crystal Point Defect laser on InGaAsP/InP
    Journal of Crystal Growth, 2006
    Co-Authors: Wanhua Zheng, Gang Ren, X.h. Cai, Liang Chen, Kengo Nozaki, Toshihiko Baba
    Abstract:

    In this paper, we focus on the dipole mode of the two-dimensional (2D) photonic Crystal (PC) single Point Defect cavity (SPDC) lasers and we report the fabrication and characterization of 2D PC SPDC lasers with the structure of adjusted innermost air holes. The photonic band and cavity Q factors are simulated by means of plane wave expansion (PWE) and finite-difference time-domain (FDTD), respectively. In order to improve the optical confinement of the SPDC, the diameter of the innermost holes was adjusted. Different lasing performances are observed experimentally. The experimental results agree with the theoretical prediction very well.

  • observation of fast spontaneous emission decay in gainasp photonic Crystal Point Defect nanocavity at room temperature
    Applied Physics Letters, 2004
    Co-Authors: Toshihiko Baba, K. Inoshita, Kengo Nozaki, D Sano, Yusuke Kuroki, Fumio Koyama
    Abstract:

    The spontaneous emission decay in a photonic Crystal slab nanocavity with a GaInAsP quantum well active region was measured at room temperature. Even far below lasing threshold, the decay was much faster than that for the as-grown wafer. A consideration including the enhanced spontaneous emission rate by the Purcell effect, intraband relaxation of carriers, nonradiative surface recombination, spatial hole burning, and carrier diffusion enabled us to explain different decay lifetime between on- and off-resonant conditions and between different size cavities. As a result, >16-fold shorter spontaneous emission lifetime was estimated, which strongly suggests the existence of a large Purcell effect.