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)

Comparison of 40GHz optical demultiplexers using SMZ switch and EA modulator in 160Gbit/s-500km OTDM transmission. - Toshihiko Hirooka; Takashi Kumakura; Kou Osawa; Masataka Nakazawa (IEICE Electron. Express, 2006)

ABCD matrix formalism of time-domain optical Fourier transformation for distortion-free pulse transmission. - Masataka Nakazawa; Toshihiko Hirooka (IEICE Electron. Express, 2006)

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)

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)

Single-Channel 1.28 Tbit/s-525 km DQPSK Transmission Using Ultrafast Time-Domain Optical Fourier Transformation and Nonlinear Optical Loop Mirror. - Pengyu Guan; Hans Christian Hansen Mulvad; Yutaro Tomiyama; Toshiyuki Hirano; Toshihiko Hirooka; Masataka Nakazawa (IEICE Trans. Commun., 2011)

Large PMD tolerant 1.28 Tbit/s/ch transmission over 525 km with 640 Gbaud optical Nyquist pulses. - Koudai Harako; Peng Ruan; Toshihiko Hirooka; 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)

Surface Roughness Control Based on Digital Copy Milling Concept to Achieve Autonomous Milling Operation. - Toshihiko Hirooka; Tomokazu Kobayashi; Atsushi Hakotani; Ryuta Sato; Keiichi Shirase (Int. J. Autom. Technol., 2013)

Novel ultrafast TDM demultiplexing scheme using orthogonality in coherent Nyquist pulses. - Koudai Harako; David Odeke Otuya; Keisuke Kasai; Toshihiko Hirooka; Masataka Nakazawa (ECOC, 2014)

A single-channel 960 Gbit/s 64 QAM orthogonal TDM transmission with a spectral efficiency of 10.0 bit/s/Hz using coherent Nyquist pulses. - David Odeke Otuya; Koudai Harako; Keisuke Kasai; Toshihiko Hirooka; Masataka Nakazawa (ECOC, 2014)

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)

100 Gbit/s DP-QPSK transmission over a 32 km legacy multi-mode GI fiber using a real-time digital coherent transceiver. - Toshihiko Hirooka; Masataka Nakazawa; Tetsuro Komukai; Toshikazu Sakano (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)

All-optical high-performance demultiplexing using optical Nyquist pulse sampling. - Daiki Seya; Koudai Harako; Toshihiko Hirooka; Masataka Nakazawa (OFC, 2014)

100 Gbit/s real-time digital coherent transmission over a 32 km legacy multi-mode graded-index fiber. - Toshihiko Hirooka; Masataka Nakazawa; Tetsuro Komukai; Toshikazu Sakano (IEICE Electron. Express, 2014)

Plug-and-Play Optical Interconnection Using Digital Coherent Technology for Resilient Network Based on Movable and Deployable ICT Resource Unit. - Tetsuro Komukai; Hirokazu Kubota; Toshikazu Sakano; Toshihiko Hirooka; Masataka Nakazawa (IEICE Trans. Commun., 2014)

Tool Motion Control Referring to Voxel Information of Removal Volume Voxel Model to Achieve Autonomous Milling Operation. - Tomokazu Kobayashi; Toshihiko Hirooka; Atsushi Hakotani; Ryuta Sato; Keiichi Shirase (Int. J. Autom. Technol., 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)

Single-channel 1.92 Tbit/s, 64 QAM coherent orthogonal TDM transmission of 160 Gbaud optical Nyquist pulses with 10.6 bit/s/Hz spectral efficiency. - David Odeke Otuya; Koudai Harako; Keisuke Kasai; Toshihiko Hirooka; Masataka Nakazawa (OFC, 2015)

Ad-hoc photonic network based on movable and deployable ICT resource unit to meet rapidly changing service demands. - Toshikazu Sakano; Tetsuro Komukai; Atsushi Takahara; Toshihiko Hirooka; Masataka Nakazawa (OFC, 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)

First demonstration of digital coherent transmission in a deployed ROADM network with a 120 Gbit/s polarization-multiplexed 64 QAM signal. - Toshihiko Hirooka; Keisuke Kasai; Yixin Wang 011; Masataka Nakazawa; Masaki Shiraiwa; Yoshinari Awaji; Naoya Wada (IEICE Electron. Express, 2015)

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)

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)

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)

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)

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)

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)

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)