Frequency nondegenerate optical parametric phase-sensitive amplifier repeater by using recovered pump carrier generated from phase-conjugated twin waves. - Yasuhiro Okamura; Kotaro Kondo; Shingo Seki; Yuya Ohmichi; Masafumi Koga; Atsushi Takada (OFC, 2016)

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)

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)

Wavelength-Conversion Free Optical Phase Conjugator Based on Difference Frequency Generation. - Yasuhiro Okamura; Shunsuke Noami; Atsushi Takada (OECC/PSC, 2019)

Optical QPSK Signal Quality Degradation due to Phase Error of Pump Light in Optical Parametric Phase-Sensitive Amplifier Repeaters. - Takeshi Kimura; Yasuhiro Okamura; Atsushi Takada (IEICE Trans. Commun., 2019)

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)

Amplitude noise suppression of BPSK signals using transmission optical fibers and optical parametric phase-sensitive amplifiers. - Akira Tanaka; Yasuhiro Okamura; Atsushi Takada (IEICE Electron. Express, 2022)