Real-Time N2O Gas Detection System for Agricultural Production Using a 4.6-µm-Band Laser Source Based on a Periodically Poled LiNbO3 Ridge Waveguide. - Akio Tokura; Masaki Asobe; Koji Enbutsu; Toshihiro Yoshihara; Shin-nosuke Hashida; Hirokazu Takenouchi (Sensors, 2013)

First demonstration of PDM signal amplification using PPLN-based polarization-independent phase sensitive amplifier. - Takeshi Umeki; Takushi Kazama; Osamu Tadanaga; Koji Enbutsu; Masaki Asobe; Yutaka Miyamoto; Hirokazu Takenouchi (ECOC, 2014)

Low noise and regenerative phase sensitive amplifier based on PPLN waveguides. - Takeshi Umeki; Masaki Asobe; H. Takara; Osamu Tadanaga; Koji Enbutsu; Yutaka Miyamoto; Hirokazu Takenouchi (OFC, 2014)

Low-noise phase-sensitive amplifier for guard-band-less 16-channel DWDM signal using PPLN waveguides. - Takushi Kazama; Takeshi Umeki; Masashi Abe; Koji Enbutsu; Yutaka Miyamoto; Hirokazu Takenouchi (OFC, 2016)

PPLN-Based Low-Noise In-Line Phase Sensitive Amplifier with Highly Sensitive Carrier-Recovery System. - Koji Enbutsu; Takeshi Umeki; Osamu Tadanaga; Masaki Asobe; Hirokazu Takenouchi (IEICE Trans. Commun., 2016)

Towards Practical Implementation of Optical Parametric Amplifiers Based on PPLN Waveguides. - Takeshi Umeki; Takushi Kazama; Takayuki Kobayashi; Koji Enbutsu; Osamu Tadanaga; Hirokazu Takenouchi; Ryoichi Kasahara; Yutaka Miyamoto (OFC, 2018)

Polarization-diversity In-line Phase Sensitive Amplifier for Simultaneous Amplification of Fiber-transmitted WDM PDM-16QAM Signals. - Takeshi Umeki; Takushi Kazama; Takayuki Kobayashi; Shigehiro Takasaka; Yasuhiro Okamura; Koji Enbutsu; Osamu Tadanaga; Hirokazu Takenouchi; Ryuichi Sugizaki; Atsushi Takada; Ryoichi Kasahara; Yutaka Miyamoto (OFC, 2018)

Scaling advantages of all-to-all connectivity in physical annealers: the Coherent Ising Machine vs. D-Wave 2000Q. - Ryan Hamerly; Takahiro Inagaki; Peter L. McMahon; Davide Venturelli; Alireza Marandi; Tatsuhiro Onodera; Edwin Ng; Carsten Langrock; Kensuke Inaba; Toshimori Honjo; Koji Enbutsu; Takeshi Umeki; et al. (CoRR, 2018)

Low-Noise Phase Sensitive Amplification Using an Optical Phase-Locked Pump. - Takushi Kazama; Takeshi Umeki; Yasuhiro Okamura; Koji Enbutsu; Osamu Tadanaga; Atsushi Takada; Ryoichi Kasahara (OECC/PSC, 2019)

1.4μm-1.6μm Wavelength Conversion Using Multiple Quasi-Phase Matching LiNbO3. - Saroeun Punhavan; Masato Kato; Keisuke Sugiyama; Masaki Asobe; Takeshi Umeki; Koji Enbutsu; Takushi Kazama; Takahiro Kashiwazaki; Ryoichi Kasahara (OECC/PSC, 2019)

Nonlinearity mitigation of PDM-16QAM signal using multiple CSI-OPCs in ultra-long haul transmission without excess penalty. - Takeshi Umeki; Takayuki Kobayashi; Akihide Sano; Takuya Ikuta; Masashi Abe; Takushi Kazama; Koji Enbutsu; Ryoichi Kasahara; Yutaka Miyamoto (OECC/PSC, 2019)

Gain Ripple and Passband Narrowing Due to Residual Chromatic Dispersion in Non-Degenerate Phase-Sensitive Amplifiers. - Shimpei Shimizu; Takushi Kazama; Takayuki Kobayashi; Takeshi Umeki; Koji Enbutsu; Ryoichi Kasahara; Yutaka Miyamoto (OFC, 2020)

Collective and synchronous dynamics of photonic spiking neurons. - Takahiro Inagaki; Kensuke Inaba; Timothée G. Leleu; Toshimori Honjo; Takuya Ikuta; Koji Enbutsu; Takeshi Umeki; Ryoichi Kasahara; Kazuyuki Aihara; Hiroki Takesue (CoRR, 2020)

PPLN-Based Low-Noise Phase Sensitive Amplification Using an Optical Phase-Locked Pump. - Takushi Kazama; Takeshi Umeki; Yasuhiro Okamura; Koji Enbutsu; Osamu Tadanaga; Atsushi Takada; Ryoichi Kasahara (IEICE Trans. Commun., 2020)

Nonlinearity Mitigation of PDM-16QAM Signals Using Multiple CSI-OPCs in Ultra-Long-Haul Transmission without Excess Penalty. - Takeshi Umeki; Takayuki Kobayashi; Akihide Sano; Takuya Ikuta; Masashi Abe; Takushi Kazama; Koji Enbutsu; Ryoichi Kasahara; Yutaka Miyamoto (IEICE Trans. Commun., 2020)

8-Tbps (20 × 400 Gbps) Unrepeated Transmission over 80 km with 2-THz PPLN-Based Phase-Sensitive Amplification Using Precise Chromatic Dispersion Pre-Compensation. - Shimpei Shimizu; Takayuki Kobayashi; Takushi Kazama; Takeshi Umeki; Masanori Nakamura; Koji Enbutsu; Ryoichi Kasahara; Yutaka Miyamoto (ECOC, 2021)

Wideband PPLN-based optical parametric amplifiers for scalable optical transport network. - Yutaka Miyamoto; Takayuki Kobayashi; Takeshi Umeki; Takushi Kazama; Koji Enbutsu; Shimpei Shimizu; Ryoichi Kasahara (OFC, 2021)

Generation of Carrier-Synchronized PDM Signal-Idler Pair for Polarization-Independent Phase-Sensitive Amplification. - Shimpei Shimizu; Takushi Kazama; Takeshi Umeki; Takayuki Kobayashi; Koji Enbutsu; Kei Watanabe; Yutaka Miyamoto (OECC/PSC, 2022)

Channel Arrangement Design in Lumped Amplified WDM Transmission over NZ-DSF Link with Nonlinearity Mitigation Using Optical Phase Conjugation. - Shimpei Shimizu; Takayuki Kobayashi; Takeshi Umeki; Takushi Kazama; Koji Enbutsu; Ryoichi Kasahara; Yutaka Miyamoto (IEICE Trans. Commun., 2022)

Experimental Demonstration of Cascadable PPLN-Based Inter-Band Wavelength Converters for Band-Switchable Multi-Band Optical Cross-Connect. - Haruka Minami; Kenta Hirose; Takafumi Fukatani; Masahiro Nakagawa; Takeshi Seki; Shimpei Shimizu; Takayuki Kobayashi; Takushi Kazama; Koji Enbutsu; Kei Watanabe; Takeshi Umeki; Takashi Miyamura; et al. (OFC, 2023)

38.4-Tbps Inline-amplified Transmission Using PPLN-based Optical Parametric Amplifier over 6 THz within L- and U-bands. - Shimpei Shimizu; Takayuki Kobayashi; Akira Kawai; Takushi Kazama; Masanori Nakamura; Koji Enbutsu; Takahiro Kashiwazaki; Masashi Abe; Takeshi Umeki; Yutaka Miyamoto; Tomoyuki Kato; Yu Tanaka; et al. (OFC, 2023)

Cascadability of PPLN-Based Inter-Band Wavelength Conversion for Band-Switchable Multi-Band Optical Cross-Connect. - Haruka Minami; Takafumi Fukatani; Masahiro Nakagawa; Takeshi Seki; Shimpei Shimizu; Takayuki Kobayashi; Takushi Kazama; Koji Enbutsu; Takeshi Umeki; Rie Hayashi; Takeshi Kuwahara (OFC, 2024)

PPLN-Based Polarization-Diverse Phase-Sensitive Amplification of 96-Gbaud PDM-PCS-64QAM Signal with Carrier-Phase-Locked Phase-Conjugated Twin Waves. - Shimpei Shimizu; Takushi Kazama; Takeshi Umeki; Koji Enbutsu; Masanori Nakamura; Masashi Abe; Takayuki Kobayashi; Yutaka Miyamoto (OFC, 2024)

9-THz Wideband PPLN-Based Wavelength Converter for Simultaneous Conversion of C+L-Band WDM Signal to Full S-Band. - Shunya Konno; Shimpei Shimizu; Masashi Abe; Takushi Kazama; Koji Enbutsu; Takahiro Kashiwazaki; Masanori Nakamura; Takayuki Kobayashi; Yutaka Miyamoto; Takeshi Umeki (OFC, 2025)

27-THz ISRS-Supported Transmission Over 1040 km in S+C+L+U and Extreme Longer-Wavelength Band. - Shimpei Shimizu; Kosuke Kimura; Akira Kawai; Masashi Abe; Shunya Konno; Takushi Kazama; Masanori Nakamura; Fukutaro Hamaoka; Koji Enbutsu; Takahiro Kashiwazaki; Munehiko Nagatani; Hitoshi Wakita; et al. (OFC, 2025)