Keisuke Kasai

53 papers B 2Misc 1Journal 12Unranked 38
YearRankTypeTitle / Venue / Authors
2025 — conf
Novel Polarization-Dependence-Free Optical Injection-Locking Circuit Using $\lambda / 4$ Phase-Shift-Free HR DFB LD at $1.5 \mu ~\mathrm{m}$.
ECOC
Keisuke Kasai, Shun Otsu, Masato Yoshida, Toshihiko Hirooka, Masataka Nakazawa
2024 — conf
New GAWBS Noise Interacting with Longitudinally Propagating Acoustic Waves in Few-mode Fibers.
OFC
Masato Yoshida, Takaaki Hirai, Shohei Beppu, Keisuke Kasai, Toshihiko Hirooka, Masataka Nakazawa, Yuta Wakayama, Noboru Yoshikane
2023 — conf
Conversion Gain Enhancement of a UTC-PD-Integrated HEMT Photonic Double-Mixer by High-Intensity Optical Subcarrier Signal.
OFC
Dai Nakajima, Kazuki Nishimura, Mitsuki Watanabe, Tsung-Tse Lin, Keisuke Kasai, Masato Yoshida, Tetsuya Suemitsu, Taiichi Otsuji, Akira Satou
2023 J jnl
Demodulation Performance Comparison of High-Speed Coherent Nyquist Pulse Signal with Analog and Digital Demultiplexing Schemes.
IEICE Trans. Commun.
Masato Yoshida, Kosuke Kimura, Toshihiko Hirooka, Keisuke Kasai, Masataka Nakazawa
2022 — conf
Demodulation Performance Comparison of 160 Gbaud Coherent Nyquist Pulse Signal with Analog and Digital DEMUX Schemes.
OECC/PSC
Masato Yoshida, Kosuke Kimura, Keisuke Kasai, Toshihiko Hirooka, Masataka Nakazawa
2022 J jnl
Experimental and Numerical Analysis of Ultrahigh-Speed Coherent Nyquist Pulse Transmission with Low-Nonlinearity Dispersion Compensator.
IEICE Trans. Commun.
Kosuke Kimura, Masato Yoshida, Keisuke Kasai, Toshihiko Hirooka, Masataka Nakazawa
2022 J jnl
Precise Measurements and their Analysis of GAWBS-Induced Depolarization Noise in Multi-Core Fiber for Digital Coherent Transmission.
IEICE Trans. Commun.
Masato Yoshida, Kozo Sato, Toshihiko Hirooka, Keisuke Kasai, Masataka Nakazawa
2021 — conf
64 Gbit/s, 256 QAM Transmission Through Coherent Optical-Wireless Link at 61 GHz Using Simple and High OSNR Carrier Frequency Converter.
OFC
Keisuke Kasai, Taisei Sato, Toshihiko Hirooka, Masato Yoshida, Masataka Nakazawa
2021 — conf
Broadband Dynamic Injection-Locking Performance of Fabry-Perot LD and Its Application to Coherent Homodyne Receiver.
OFC
Takashi Kan, Keisuke Kasai, Masato Yoshida, Toshihiko Hirooka, Masataka Nakazawa
2021 — conf
GAWBS Noise Correlation Between Cores in Four-Core Fiber.
OFC
Kozo Sato, Masato Yoshida, Keisuke Kasai, Toshihiko Hirooka, Masataka Nakazawa
2020 — conf
10 GHz, 6.2 ps Transform-Limited Coherent Optical Pulse Generation from a 1.55 μm, Self-Injection Gain-Switched DFB-LD.
OFC
Keisuke Kasai, Masataka Nakazawa
2020 — conf
10 Tbit/s QAM Quantum Noise Stream Cipher Coherent Transmission over 160 km.
OFC
Masato Yoshida, Takashi Kan, Keisuke Kasai, Toshihiko Hirooka, Masataka Nakazawa
2020 — conf
64 Gbit/s, 256 QAM Coherently-Linked Optical and Wireless Transmission in 61 GHz Band Using Novel Injection-Locked Carrier Frequency Converter.
ECOC
Keisuke Kasai, Toshihiko Hirooka, Masato Yoshida, Masataka Nakazawa
2020 — conf
Experimental and Theoretical Analyses of GAWBS Phase Noise in Multi-Core Fiber for Digital Coherent Transmission.
OFC
Naoya Takefushi, Masato Yoshida, Keisuke Kasai, Toshihiko Hirooka, Masataka Nakazawa
2020 B conf
Research Project to Realize Various High-reliability Communications in Advanced 5G Network.
WCNC
Takahide Murakami, Yoji Kishi, Koji Ishibashi, Keisuke Kasai, Hiroyuki Shinbo, Morihiko Tamai, Kensuke Tsuda, Masataka Nakazawa, Yu Tsukamoto, Hiroyuki Yokoyama, Yoshimi Fujii, Yuta Seki, Shinobu Nanba, Takanori Hara, Fumiyuki Adachi, Takayuki Sotoyama
2019 — conf
Dual-Polarization On-Line 256 and 512 QAM Digital Coherent Transmission.
OFC
Masato Yoshida, Keisuke Kasai, Toshihiko Hirooka, Masataka Nakazawa
2019 — conf
GAWBS Noise Characteristics in Digital Coherent Transmission in Various Optical Fibers.
OECC/PSC
Naoya Takefushi, Masato Yoshida, Keisuke Kasai, Toshihiko Hirooka, Masataka Nakazawa
2019 — conf
Real-Time 256 QAM Bi-directional Coherent Transmission in Next Generation Mobile Fronthaul.
OECC/PSC
Masato Yoshida, Takashi Kan, Keisuke Kasai, Toshihiko Hirooka, Masataka Nakazawa
2018 — conf
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.
OFC
Masaki Terayama, Seiji Okamoto, Keisuke Kasai, Masato Yoshida, Masataka Nakazawa
2018 — conf
Backward-Rayleigh-Scattering Suppressed 160 Gbit/s 256 QAM Injection-Locked Bidirectional Coherent Transmission for Next Generation Mobile Fronthaul.
ECOC
Keisuke Kasai, Masato Yoshida, Toshihiko Hirooka, Katsumi Iwatsuki, Masataka Nakazawa
2018 — conf
Experimental and Numerical Comparison of Probabilistically-Shaped 4096 QAM and Uniformly-Shaped 1024 QAM in All-Raman Amplified 160 km Transmission.
OFC
Seiji Okamoto, Masaki Terayama, Masato Yoshida, Keisuke Kasai, Toshihiko Hirooka, Masataka Nakazawa
2018 — conf
Injection-locked Homodyne Detection for Higher-order QAM Transmission.
OFC
Keisuke Kasai, Yixin Wang, Masato Yoshida, Toshihiko Hirooka, Masataka Nakazawa
2018 — conf
Observation of Guided Acoustic-Wave Brillouin Scattering and its Digital Compensation in Coherent QAM Transmission.
OFC
Masataka Nakazawa, Masaki Terayama, Seiji Okamoto, Masato Yoshida, Keisuke Kasai, Toshihiko Hirooka
2017 — conf
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.
OFC
Takashi Kan, Keisuke Kasai, Masato Yoshida, Masataka Nakazawa
2017 — conf
80 Gbit/s/ch, 256 QAM Digital Coherent Optical Transmission System with Injection-Locking for Next Generation Mobile Fronthaul Network.
ECOC
Keisuke Kasai, Yixin Wang, Masato Yoshida, Toshihiko Hirooka, Katsumi Iwatsuki, Masataka Nakazawa
2017 — conf
A New Optical Phase-Locked System Between Ultrashort Pulses for 640 Gbaud Nyquist OTDM Coherent QAM Transmission.
ECOC
Kosuke Kimura, Junpei Nitta, Masato Yoshida, Keisuke Kasai, Toshihiko Hirooka, Masataka Nakazawa
2017 — conf
Full C-band, mode-hop-free wavelength-tunable laser diode with a linewidth of 8 kHz and a RIN of -130 dB/Hz.
OFC
Keisuke Kasai, Masataka Nakazawa, Yasunori Tomomatsu, Takashi Endo
2017 — conf
Single-carrier 216 Gbit/s, 12 Gsymbol/s 512 QAM coherent transmission over 160 km with injection-locked homodyne detection.
OFC
Yixin Wang, Keisuke Kasai, Masato Yoshida, Masataka Nakazawa
2017 — conf
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.
ECOC
Keisuke Kasai, Toshihiko Hirooka, Masato Yoshida, Masataka Nakazawa, Masaki Shiraiwa, Yoshinari Awaji, Naoya Wada
2017 — conf
Single-channel 3.84 Tbit/s, 64 QAM coherent Nyquist pulse transmission over 150 km with frequency-stabilized and mode-locked laser.
OFC
Masato Yoshida, Junpei Nitta, Kosuke Kimura, Keisuke Kasai, Toshihiko Hirooka, Masataka Nakazawa
2016 — conf
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.
OFC
Keisuke Kasai, Masato Yoshida, Masataka Nakazawa
2015 — conf
256 QAM (polarization-multiplexed, 5 Gsymbol/s) coherent transmission with an injection-locked homodyne detection technique.
OFC
Keisuke Kasai, Shohei Beppu, Yixin Wang, Masataka Nakazawa
2015 J jnl
First demonstration of digital coherent transmission in a deployed ROADM network with a 120 Gbit/s polarization-multiplexed 64 QAM signal.
IEICE Electron. Express
Toshihiko Hirooka, Keisuke Kasai, Yixin Wang, Masataka Nakazawa, Masaki Shiraiwa, Yoshinari Awaji, Naoya Wada
2015 Misc conf
QAM quantum noise stream cipher using digital coherent optical transmission.
ACSSC
Masato Yoshida, Toshihiko Hirooka, Keisuke Kasai, Masataka Nakazawa
2015 — conf
Real-time 10 Gbit/s-16 QAM quantum stream cipher transmission over 320 km with FPGA-based transmitter and receiver.
OFC
Masato Yoshida, Toshihiko Hirooka, Keisuke Kasai, Masataka Nakazawa
2015 — conf
Real-time adaptive 4-64 QAM, 20-60 Gbit/s quantum noise stream cipher transmission over 320 km with FPGA-based transmitter and receiver.
ECOC
Masato Yoshida, Toshihiko Hirooka, Keisuke Kasai, Masataka Nakazawa
2015 — conf
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.
OFC
David Odeke Otuya, Koudai Harako, Keisuke Kasai, Toshihiko Hirooka, Masataka Nakazawa
2014 — conf
1.92 Tbit/s, 64 QAM coherent Nyquist pulse transmission over 150 km with a spectral efficiency of 7.5 bit/s/Hz.
OFC
David Odeke Otuya, Keisuke Kasai, Toshihiko Hirooka, Masato Yoshida, Masataka Nakazawa
2014 — conf
2048 QAM (66 Gbit/s) single-carrier coherent optical transmission over 150 km with a potential SE of 15.3 bit/s/Hz.
OFC
Shohei Beppu, Keisuke Kasai, Masato Yoshida, Masataka Nakazawa
2014 J jnl
60 Gbit/s, 64 QAM LD-based injection-locked coherent heterodyne transmission over 160 km with a spectral efficiency of 9 bit/s/Hz.
IEICE Electron. Express
Yixin Wang, Keisuke Kasai, Masato Yoshida, Masataka Nakazawa
2014 — conf
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.
ECOC
David Odeke Otuya, Koudai Harako, Keisuke Kasai, Toshihiko Hirooka, Masataka Nakazawa
2014 — conf
Novel ultrafast TDM demultiplexing scheme using orthogonality in coherent Nyquist pulses.
ECOC
Koudai Harako, David Odeke Otuya, Keisuke Kasai, Toshihiko Hirooka, Masataka Nakazawa
2014 — conf
Real-time adaptive 4-64 QAM coherent optical transmission over 320 km with FPGA-based transmitter and receiver.
ECOC
Masato Yoshida, Toshihiko Hirooka, Keisuke Kasai, Masataka Nakazawa
2013 — conf
A single-channel, 1.6 Tbit/s 32 QAM coherent pulse transmission over 150 km with RZ-CW conversion and FDE techniques.
OFC/NFOEC
David Odeke Otuya, Keisuke Kasai, Toshihiko Hirooka, Masato Yoshida, Masataka Nakazawa, Tokutaka Hara, Satoshi Oikawa
2013 — conf
An LD-based ultra-low phase noise opll circuit using an optical voltage controlled oscillator.
OFC/NFOEC
Keisuke Kasai, Yixin Wang, Masataka Nakazawa
2011 J jnl
256 QAM Digital Coherent Optical Transmission Using Raman Amplifiers.
IEICE Trans. Commun.
Masato Yoshida, Seiji Okamoto, Tatsunori Omiya, Keisuke Kasai, Masataka Nakazawa
2011 J jnl
Polarization-multiplexed, 10Gsymbol/s, 64QAM coherent transmission over 150km with OPLL-based homodyne detection employing narrow linewidth LDs.
IEICE Electron. Express
Yixin Wang, Keisuke Kasai, Masataka Nakazawa
2010 J jnl
60Gbit/s 64 QAM-OFDM coherent optical transmission with a 5.3GHz bandwidth.
IEICE Electron. Express
Tatsunori Omiya, Seiji Okamoto, Keisuke Kasai, Masato Yoshida, Masataka Nakazawa
2010 B conf
STRAC: Personal Information Access Control for Emergency Systems.
SERVICES
Kyoji Kawagoe, Keisuke Kasai
2008 J jnl
Polarization and frequency division multiplexed 1Gsymbol/s, 64 QAM coherent optical transmission with 8.6bit/s/Hz spectral efficiency over 160km.
IEICE Electron. Express
Hiroki Goto, Masato Yoshida, Tatsunori Omiya, Keisuke Kasai, Masataka Nakazawa
2008 J jnl
The use of a Nyquist filter for reducing an optical signal bandwidth in a coherent QAM optical transmission.
IEICE Electron. Express
Keisuke Kasai, Jumpei Hongo, Hiroki Goto, Masato Yoshida, Masataka Nakazawa
2007 J jnl
Optical phase-locked loop for coherent transmission over 500km using heterodyne detection with fiber lasers.
IEICE Electron. Express
Keisuke Kasai, Jumpei Hongo, Masato Yoshida, Masataka Nakazawa
2006 J jnl
Performance improvement of an acetylene (C
IEICE Electron. Express
Keisuke Kasai, Akihito Suzuki, Masato Yoshida, Masataka Nakazawa