10Gb/s transmission over 5km at 850nm using single-mode photonic crystal fiber, single-mode VCSEL, and Si-APD. - Hideaki Hasegawa; Yosuke Oikawa; Masato Yoshida; Toshihiko Hirooka; Masataka Nakazawa (IEICE Electron. Express, 2006)

Performance improvement of an acetylene (C2H2) frequency-stabilized fiber laser. - Keisuke Kasai; Akihito Suzuki; Masato Yoshida; Masataka Nakazawa (IEICE Electron. Express, 2006)

Optical phase-locked loop for coherent transmission over 500km using heterodyne detection with fiber lasers. - Keisuke Kasai; Jumpei Hongo; Masato Yoshida; Masataka Nakazawa (IEICE Electron. Express, 2007)

A CW, polarization-maintaining λ/4-shifted DFB Er-doped fiber laser at 1.54µm. - Akihito Suzuki; Youhei Takahashi; Masato Yoshida; Masataka Nakazawa (IEICE Electron. Express, 2007)

Ultra-Stable Regeneratively Mode-Locked Laser as an Opto-Electronic Microwave Oscillator and Its Application to Optical Metrology. - Masataka Nakazawa; Masato Yoshida; Toshihiko Hirooka (IEICE Trans. Electron., 2007)

Polarization and frequency division multiplexed 1Gsymbol/s, 64 QAM coherent optical transmission with 8.6bit/s/Hz spectral efficiency over 160km. - Hiroki Goto; Masato Yoshida; Tatsunori Omiya; Keisuke Kasai; Masataka Nakazawa (IEICE Electron. Express, 2008)

The use of a Nyquist filter for reducing an optical signal bandwidth in a coherent QAM optical transmission. - Keisuke Kasai; Jumpei Hongo; Hiroki Goto; Masato Yoshida; Masataka Nakazawa (IEICE Electron. Express, 2008)

10Gbit/s photonic crystal fiber transmissions with 1.1µm directly-modulated single-mode VCSEL. - Kengo Koizumi; Masato Yoshida; Toshihiko Hirooka; Masataka Nakazawa (IEICE Electron. Express, 2009)

Optical frequency-tunable Cs atomic clock with a 9.19GHz mode-hop-free fiber laser. - Takahito Morisaki; Masato Yoshida; Masataka Nakazawa (IEICE Electron. Express, 2010)

60Gbit/s 64 QAM-OFDM coherent optical transmission with a 5.3GHz bandwidth. - Tatsunori Omiya; Seiji Okamoto; Keisuke Kasai; Masato Yoshida; Masataka Nakazawa (IEICE Electron. Express, 2010)

256 QAM Digital Coherent Optical Transmission Using Raman Amplifiers. - Masato Yoshida; Seiji Okamoto; Tatsunori Omiya; Keisuke Kasai; Masataka Nakazawa (IEICE Trans. Commun., 2011)

A Cesium optical atomic clock with high optical frequency stability. - Kazunari Tokuhira; Fumitaka Suzuki; Masato Yoshida; Masataka Nakazawa (IEICE Electron. Express, 2012)

400 Gbit/s 256 QAM-OFDM transmission over 720 km with a 14 bit/s/Hz spectral efficiency using an improved FDE technique. - Tatsunori Omiya; Masato Yoshida; Masataka Nakazawa (OFC/NFOEC, 2013)

A single-channel, 1.6 Tbit/s 32 QAM coherent pulse transmission over 150 km with RZ-CW conversion and FDE techniques. - David Odeke Otuya; Keisuke Kasai; Toshihiko Hirooka; Masato Yoshida; Masataka Nakazawa; Tokutaka Hara; Satoshi Oikawa (OFC/NFOEC, 2013)

Multicore EDFA for DWDM transmission in full C-band. - Yukihiro Tsuchida; Koichi Maeda; Kengo Watanabe; Toshiharu Ito; Kiyoshi Fukuchi; Masato Yoshida; Yu Mimura; Ryuichi Sugizaki; Masataka Nakazawa (OFC/NFOEC, 2013)

OH-free low loss single-mode fibre fabricated by slurry casting / rod-in-tube method. - Tamotsu Yajima; Jun Yamamoto; Yusuke Kinoshita; Futoshi Ishii; Toshihiko Hirooka; Masato Yoshida; Masataka Nakazawa (ECOC, 2014)

Real-time adaptive 4-64 QAM coherent optical transmission over 320 km with FPGA-based transmitter and receiver. - Masato Yoshida; Toshihiko Hirooka; Keisuke Kasai; Masataka Nakazawa (ECOC, 2014)

2048 QAM (66 Gbit/s) single-carrier coherent optical transmission over 150 km with a potential SE of 15.3 bit/s/Hz. - Shohei Beppu; Keisuke Kasai; Masato Yoshida; Masataka Nakazawa (OFC, 2014)

Measurement of mode coupling distribution along a few-mode fiber using a synchronous multi-channel OTDR. - Masataka Nakazawa; Masato Yoshida; Toshihiko Hirooka (OFC, 2014)

1.92 Tbit/s, 64 QAM coherent Nyquist pulse transmission over 150 km with a spectral efficiency of 7.5 bit/s/Hz. - David Odeke Otuya; Keisuke Kasai; Toshihiko Hirooka; Masato Yoshida; Masataka Nakazawa (OFC, 2014)

60 Gbit/s, 64 QAM LD-based injection-locked coherent heterodyne transmission over 160 km with a spectral efficiency of 9 bit/s/Hz. - Yixin Wang 011; Keisuke Kasai; Masato Yoshida; Masataka Nakazawa (IEICE Electron. Express, 2014)

QAM quantum noise stream cipher using digital coherent optical transmission. - Masato Yoshida; Toshihiko Hirooka; Keisuke Kasai; Masataka Nakazawa (ACSSC, 2015)

Real-time adaptive 4-64 QAM, 20-60 Gbit/s quantum noise stream cipher transmission over 320 km with FPGA-based transmitter and receiver. - Masato Yoshida; Toshihiko Hirooka; Keisuke Kasai; Masataka Nakazawa (ECOC, 2015)

Real-time 10 Gbit/s-16 QAM quantum stream cipher transmission over 320 km with FPGA-based transmitter and receiver. - Masato Yoshida; Toshihiko Hirooka; Keisuke Kasai; Masataka Nakazawa (OFC, 2015)

A 295 mW output, HCN frequency-stabilized CW erbium silica fiber laser with a linewidth of 5 kHz and a RIN of -120 dB/Hz. - Keisuke Kasai; Masato Yoshida; Masataka Nakazawa (OFC, 2016)

Fused type fan-out device for multi-core fiber based on bundled structure. - Masato Yoshida; Toshihiko Hirooka; Masataka Nakazawa (OFC, 2016)

Mode coupling measurement at a splice point between few-mode fibers using a synchronous multi-channel OTDR. - Masato Yoshida; Toshihiko Hirooka; Masataka Nakazawa (OFC, 2016)

A 1.55 µm, 271 fs and 1.07 µm, 294 fs simultaneously mode-locked Er- and Yb-doped fiber laser with a single SWNT/PVA saturable absorber. - Masatoshi Nakao; Masato Yoshida; Toshihiko Hirooka; Masataka Nakazawa (IEICE Electron. Express, 2016)

Fabrication of OH-free, single-mode fiber by using slurry casting and rod-in-tube method. - Tamotsu Yajima; Jun Yamamoto; Yusuke Kinoshita; Futoshi Ishii; Toshihiko Hirooka; Masato Yoshida; Masataka Nakazawa (IEICE Electron. Express, 2016)

Single-carrier 552 Gbit/s, 46 Gbaud 64 QAM Coherent Transmission over 100 km with Co-propagating 10 Gbit/s-OOK Signals Through a Deployed ROADM Network. - Keisuke Kasai; Toshihiko Hirooka; Masato Yoshida; Masataka Nakazawa; Masaki Shiraiwa; Yoshinari Awaji; Naoya Wada (ECOC, 2017)

80 Gbit/s/ch, 256 QAM Digital Coherent Optical Transmission System with Injection-Locking for Next Generation Mobile Fronthaul Network. - Keisuke Kasai; Yixin Wang 011; Masato Yoshida; Toshihiko Hirooka; Katsumi Iwatsuki; Masataka Nakazawa (ECOC, 2017)

A New Optical Phase-Locked System Between Ultrashort Pulses for 640 Gbaud Nyquist OTDM Coherent QAM Transmission. - Kosuke Kimura; Junpei Nitta; Masato Yoshida; Keisuke Kasai; Toshihiko Hirooka; Masataka Nakazawa (ECOC, 2017)

42.3-Tbit/s, 18-Gbaud 64QAM WDM coherent transmission of 160 km over full C-band using an injection locking technique with a spectral efficiency of 9 bit/s/Hz. - Takashi Kan; Keisuke Kasai; Masato Yoshida; Masataka Nakazawa (OFC, 2017)

Single-carrier 216 Gbit/s, 12 Gsymbol/s 512 QAM coherent transmission over 160 km with injection-locked homodyne detection. - Yixin Wang 011; Keisuke Kasai; Masato Yoshida; Masataka Nakazawa (OFC, 2017)

Fabrication of multi core fiber by using slurry casting method. - Jun Yamamoto; Tamotsu Yajima; Yusuke Kinoshita; Futoshi Ishii; Masato Yoshida; Toshihiko Hirooka; Masataka Nakazawa (OFC, 2017)

Single-channel 3.84 Tbit/s, 64 QAM coherent Nyquist pulse transmission over 150 km with frequency-stabilized and mode-locked laser. - Masato Yoshida; Junpei Nitta; Kosuke Kimura; Keisuke Kasai; Toshihiko Hirooka; Masataka Nakazawa (OFC, 2017)

A 40 GHz, 770 fs regeneratively mode-locked erbium fiber laser operating at 1.6 µm. - Koudai Harako; Masato Yoshida; Toshihiko Hirooka; Masataka Nakazawa (IEICE Electron. Express, 2017)

Single-Channel 10.2 Tbit/s PDM-DQPSK Nyquist Pulse Transmission over 300 km. - Toshihiko Hirooka; Ryoya Hirata; Jianping Wang; Masato Yoshida; Masataka Nakazawa (ECOC, 2018)

Backward-Rayleigh-Scattering Suppressed 160 Gbit/s 256 QAM Injection-Locked Bidirectional Coherent Transmission for Next Generation Mobile Fronthaul. - Keisuke Kasai; Masato Yoshida; Toshihiko Hirooka; Katsumi Iwatsuki; Masataka Nakazawa (ECOC, 2018)

Injection-locked Homodyne Detection for Higher-order QAM Transmission. - Keisuke Kasai; Yixin Wang 011; Masato Yoshida; Toshihiko Hirooka; Masataka Nakazawa (OFC, 2018)

Observation of Guided Acoustic-Wave Brillouin Scattering and its Digital Compensation in Coherent QAM Transmission. - Masataka Nakazawa; Masaki Terayama; Seiji Okamoto; Masato Yoshida; Keisuke Kasai; Toshihiko Hirooka (OFC, 2018)

Secure Transmission using QAM Quantum Noise Stream Cipher with Continuous Variable QKD. - Masataka Nakazawa; Masato Yoshida; Takuya Hirano (OFC, 2018)

Experimental and Numerical Comparison of Probabilistically-Shaped 4096 QAM and Uniformly-Shaped 1024 QAM in All-Raman Amplified 160 km Transmission. - Seiji Okamoto; Masaki Terayama; Masato Yoshida; Keisuke Kasai; Toshihiko Hirooka; Masataka Nakazawa (OFC, 2018)

4096 QAM (72 Gbit/s) Single-Carrier Coherent Optical Transmission with a Potential SE of 15.8 bit/s/Hz in All-Raman Amplified 160 km Fiber Link. - Masaki Terayama; Seiji Okamoto; Keisuke Kasai; Masato Yoshida; Masataka Nakazawa (OFC, 2018)

Dual-Polarization On-Line 256 and 512 QAM Digital Coherent Transmission. - Masato Yoshida; Keisuke Kasai; Toshihiko Hirooka; Masataka Nakazawa (OFC, 2019)

Sub-Picosecond Optical Switch over Entire C-Band by Using Nonlinear Optical Loop Mirror. - Ryoya Hirata; Toshihiko Hirooka; Masato Yoshida; Masataka Nakazawa (OECC/PSC, 2019)

GAWBS Noise Characteristics in Digital Coherent Transmission in Various Optical Fibers. - Naoya Takefushi; Masato Yoshida; Keisuke Kasai; Toshihiko Hirooka; Masataka Nakazawa (OECC/PSC, 2019)

Real-Time 256 QAM Bi-directional Coherent Transmission in Next Generation Mobile Fronthaul. - Masato Yoshida; Takashi Kan; Keisuke Kasai; Toshihiko Hirooka; Masataka Nakazawa (OECC/PSC, 2019)

Wavelength-tunable sub-picosecond optical switch over entire C-band using nonlinear optical loop mirror. - Ryoya Hirata; Toshihiko Hirooka; Masato Yoshida; Masataka Nakazawa (IEICE Electron. Express, 2019)

64 Gbit/s, 256 QAM Coherently-Linked Optical and Wireless Transmission in 61 GHz Band Using Novel Injection-Locked Carrier Frequency Converter. - Keisuke Kasai; Toshihiko Hirooka; Masato Yoshida; Masataka Nakazawa (ECOC, 2020)

Experimental and Theoretical Analyses of GAWBS Phase Noise in Multi-Core Fiber for Digital Coherent Transmission. - Naoya Takefushi; Masato Yoshida; Keisuke Kasai; Toshihiko Hirooka; Masataka Nakazawa (OFC, 2020)

10 Tbit/s QAM Quantum Noise Stream Cipher Coherent Transmission over 160 km. - Masato Yoshida; Takashi Kan; Keisuke Kasai; Toshihiko Hirooka; Masataka Nakazawa (OFC, 2020)

Broadband Dynamic Injection-Locking Performance of Fabry-Perot LD and Its Application to Coherent Homodyne Receiver. - Takashi Kan; Keisuke Kasai; Masato Yoshida; Toshihiko Hirooka; Masataka Nakazawa (OFC, 2021)

64 Gbit/s, 256 QAM Transmission Through Coherent Optical-Wireless Link at 61 GHz Using Simple and High OSNR Carrier Frequency Converter. - Keisuke Kasai; Taisei Sato; Toshihiko Hirooka; Masato Yoshida; Masataka Nakazawa (OFC, 2021)

GAWBS Noise Correlation Between Cores in Four-Core Fiber. - Kozo Sato; Masato Yoshida; Keisuke Kasai; Toshihiko Hirooka; Masataka Nakazawa (OFC, 2021)

Recent progress and challenges toward ultrahigh-speed transmission beyond 10 Tbit/s with optical Nyquist pulses. - Masataka Nakazawa; Masato Yoshida; Toshihiko Hirooka (IEICE Electron. Express, 2021)

Characterization of Inter-core Crosstalk of Multi-core Fiber as a Function of Bending Radius with Multi-channel OTDR. - Yuto Kobayashi; Takahiro Suganuma; Tetsuya Hayashi; Takemi Hasegawa; Masato Yoshida; Masataka Nakazawa (OECC/PSC, 2022)

Measurement of Wide-band Modulation Characteristic in Hybrid Modulation Laser. - Takumi Shima; Masato Yoshida; Nobuhide Yokota; Wataru Kobayashi; Hiroshi Yasaka (OECC/PSC, 2022)

10.2 Tbit/s (1.28 Tbit/s/ch x 8 ch) WDM Nyquist Pulse Transmission over 2100 km. - Aoi Watanabe; Aoto Ishikawa; Masato Yoshida; Toshihiko Hirooka; Masataka Nakazawa (OECC/PSC, 2022)

Demodulation Performance Comparison of 160 Gbaud Coherent Nyquist Pulse Signal with Analog and Digital DEMUX Schemes. - Masato Yoshida; Kosuke Kimura; Keisuke Kasai; Toshihiko Hirooka; Masataka Nakazawa (OECC/PSC, 2022)

GAWBS noise in multicore fibers. - Masato Yoshida; Masataka Nakazawa (OECC/PSC, 2022)

Precise Measurements and their Analysis of GAWBS-Induced Depolarization Noise in Multi-Core Fiber for Digital Coherent Transmission. - Masato Yoshida; Kozo Sato; Toshihiko Hirooka; Keisuke Kasai; Masataka Nakazawa (IEICE Trans. Commun., 2022)

Experimental and Numerical Analysis of Ultrahigh-Speed Coherent Nyquist Pulse Transmission with Low-Nonlinearity Dispersion Compensator. - Kosuke Kimura; Masato Yoshida; Keisuke Kasai; Toshihiko Hirooka; Masataka Nakazawa (IEICE Trans. Commun., 2022)

Conversion Gain Enhancement of a UTC-PD-Integrated HEMT Photonic Double-Mixer by High-Intensity Optical Subcarrier Signal. - Dai Nakajima; Kazuki Nishimura; Mitsuki Watanabe; Tsung-Tse Lin; Keisuke Kasai; Masato Yoshida; Tetsuya Suemitsu; Taiichi Otsuji; Akira Satou (OFC, 2023)

Demodulation Performance Comparison of High-Speed Coherent Nyquist Pulse Signal with Analog and Digital Demultiplexing Schemes. - Masato Yoshida; Kosuke Kimura; Toshihiko Hirooka; Keisuke Kasai; Masataka Nakazawa (IEICE Trans. Commun., 2023)

Mode Division Multiplexed Coherent Optical Transmission in Time Domain by Using Higher-order Hermite-Gaussian Pulses. - Masataka Nakazawa; Masato Yoshida; Toshihiko Hirooka (OFC, 2024)

New GAWBS Noise Interacting with Longitudinally Propagating Acoustic Waves in Few-mode Fibers. - Masato Yoshida; Takaaki Hirai; Shohei Beppu; Keisuke Kasai; Toshihiko Hirooka; Masataka Nakazawa; Yuta Wakayama; Noboru Yoshikane (OFC, 2024)