Toshimasa Umezawa

Publication Activity (10 Years)

Years Active: 2014-2024
Publications (10 Years): 31

Top Topics

Graceful Degradation

Sample Complexity

Iso Picture Languages

Top Venues

Publications

Yaofeng Yi, Toshimasa Umezawa, Kouichi Akahane, Tetsuya Kawanishi
Thermal Study for High-Photocurrent Photodetector in Non-Saturation Region Using Thin Substrate, Thin Absorber, and Flip- Chip Bonding Process. IEEE Access 12 (2024)
Zu-Kai Weng, Yuki Yoshida, Toshimasa Umezawa, Abdelmoula Bekkali, Michikazu Hattori, Atsushi Matsumoto, Atsushi Kanno, Naokatsu Yamamoto, Tetsuya Kawanishi, Kouichi Akahane
40-Gbit/s Mobile FSO with High-speed Beam Stabilizer and 2D-PDA-based Diversity Receiver for Support Robots. OFC (2024)
Toshimasa Umezawa, Pham Tien Dat, Yuki Yoshida, Shinya Nakajima, Atsushi Matsumoto, Kouichi Akahane, Atsushi Kanno, Naokatsu Yamamoto
DC-226 GHz well-impedance-matched high-speed photoreceiver for multi-band signal detection. OFC (2024)
Yaofeng Yi, Toshimasa Umezawa, Kouichi Akahane, Tetsuya Kawanishi
High-Responsivity Unitraveling Carrier-Type Photodetector Using Avalanche InAlAs as a Collector at a High-Frequency Range. IEEE Access 12 (2024)
Zu-Kai Weng, Yuki Yoshida, Toshimasa Umezawa, Abdelmoula Bekkali, Michikazu Hattori, Atsushi Matsumoto, Atsushi Kanno, Naokatsu Yamamoto, Tetsuya Kawanishi, Kouichi Akahane
Demonstration of Robust Mobile Free Space Optical System using High-speed Beam Tracking and 2D-PDA-based Spatial-Diversity Reception. OFC (2024)
Atsushi Matsumoto, Ryota Yabuki, Shinya Nakajima, Toshimasa Umezawa, Siim Heinsalu, Yuichi Matsushima, Koichi Akahane, Naokatsu Yamamoto, Katsuyuki Utaka
Low Threshold and 10kHz-Class Narrow Linewidth 1.55 µm-Band Quantum Dot Laser Diode on InP(311)B Substrate. OFC (2024)
Toshimasa Umezawa, Atsushi Matsumoto, Kouichi Akahane, Atsushi Kanno, Naokatsu Yamamoto
100-Gbps 2-SDM 2-WDM FSO beam direct detection using resonant cavity 4x4 photodetector array. OFC (2023)
Go Soma, Yoshiro Nomoto, Toshimasa Umezawa, Yuki Yoshida, Yoshiaki Nakano, Takuo Tanemura
Self-Coherent Transmission Using Metasurface-based Stokes-Vector Receiver. OFC (2023)
Toshimasa Umezawa, Atsushi Matsumoto, Kouichi Akahane, Atsushi Kanno, Naokatsu Yamamoto
400-pixel high-speed photodetector for high optical alignment robustness FSO receiver. OFC (2022)
Yaofeng Yi, Toshimasa Umezawa, Atsushi Kanno, Tetsuya Kawanishi
50 GHz High Photocurrent PIN-PD and Its Thermal Effect. OECC/PSC (2022)
Hayato Takemura, Haruto Shinya, Yuya Yamaguchi, Toshimasa Umezawa, Atsushi Kanno, Tetsuya Kawanishi
High-Speed Beam Steering LN Optical Phased Array Module using Comb-Electrode. OECC/PSC (2022)
Siyang Duan, Toshimasa Umezawa, Atsushi Kanno, Tetsuya Kawanishi
High-Efficient Pixel Layout Arrangement in High-Speed 2-D Photodetector Array. OECC/PSC (2022)
Toshimasa Umezawa, Kunio Jitsuno, Naokatsu Yamamoto, Tetsuya Kawanishi
240-Gbps SDM-FSO communication using 4-bundle fiber and 2D photodetector array. OFC (2021)
Toshimasa Umezawa, Shinya Nakajima, Atsushi Kanno, Naokatsu Yamamoto
Submillimeter Large High-speed Photodetector for High Optical Alignment Robustness Optical Wireless Communications. ECOC (2021)
Toshimasa Umezawa, Pham Tien Dat, Atsushi Kanno, Kunihisa Jitsuno, Naokatsu Yamamoto, Tetsuya Kawanishi
30 GHz Radio over FSO System using High Speed 2D-PDA and Its Optical Path Switching Performance. ECOC (2020)
Yuki Yoshida, Toshimasa Umezawa, Atsushi Kanno, Keizo Inagaki, Naokatsu Yamamoto, Tetsuya Kawanishi
On the Sample Complexity of Phase-Retrieval Receiver Based on 2-D Arrayed Photodetectors. OFC (2020)
Yuki Yoshida, Toshimasa Umezawa, Atsushi Kanno, Naokatsu Yamamoto
Phase-Retrieving Coherent Reception and its Sample Complexity. ECOC (2020)
Toshimasa Umezawa, Yuki Yoshida, Atsushi Kanno, Naokatsu Yamamoto, Tetsuya Kawanishi
High Speed 2D-PDA FSO Receiver for High Optical Alignment Robustness with Space Diversity. OFC (2020)
Ken Kusakata, S. Takamizawa, Toshimasa Umezawa, Naokatsu Yamamoto, Tetsuya Kawanishi
Characterization of 2D high-speed photodetector array device for SDM fiber communication applications. OECC/PSC (2019)
Pham Tien Dat, Atsushi Kanno, Keizo Inagaki, Toshimasa Umezawa, Naokatsu Yamamoto, Tetsuya Kawanishi
Hybrid Optical Wireless-mmWave: Ultra High-Speed Indoor Communications for Beyond 5G. INFOCOM Workshops (2019)
Toshimasa Umezawa, Atsushi Matsumoto, Atsushi Kanno, Naokatsu Yamamoto, Tetsuya Kawanishi
1-λ, 16-Parallel Lanes, 50-Gbaud On-Off Keying Multi-Core Fiber Communication Directly Coupled to High Speed 2D-Photodetector Array. OFC (2019)
Yuki Yoshida, Toshimasa Umezawa, Atsushi Kanno, Naokatsu Yamamoto
Coherent Detection Only by 2-D Photodetector Array: A Discreteness-Aware Phase Retrieval Approach. OFC (2019)
Atsushi Kanno, Pham Tien Dat, Toshimasa Umezawa, Naokatsu Yamamoto, Tetsuya Kawanishi, Nagateru Iwasawa, Nariya Iwaki, Kazuki Nakamura, Kunihiro Kawasaki, Naoki Kanada, Naruto Yonemoto, Yosuke Sato, Masato Fujii, Katsuya Yanatori, Nobuhiko Shibagaki, Kenichi Kashima
Field Trial of 1.5-Gbps 97-GHz Train Communication System Based on Linear Cell Radio Over Fiber Network for 240-km/h High-Speed Train. OFC (2019)
Pham Tien Dat, Atsushi Kanno, Keizo Inagaki, Toshimasa Umezawa, François Rottenberg, Jérôme Louveaux, Naokatsu Yamamoto, Tetsuya Kawanishi
High-Speed and Handover-Free Communications for High-Speed Trains Using Switched WDM Fiber-Wireless System. OFC (2018)
Toshimasa Umezawa, Takahide Sakamoto, Atsushi Kanno, Shinya Nakajima, Atsushi Matsumoto, Naokatsu Yamamoto, Tetsuya Kawanishi
400-Gbps Space Division Multiplexing Optical Wireless Communication Using Two-Dimensional Photodetector Array. ECOC (2018)
Toshimasa Umezawa, Takahide Sakamoto, Atsushi Kanno, Kouichi Akahane, Atsushi Matsumoto, Naokatsu Yamamoto, Tetsuya Kawanishi
High-speed Two-dimensional Photodetector Array for 4-WDM 25-Gbaud FSO Communication. OFC (2018)
Toshimasa Umezawa, Pham Tien Dat, Eiichi Hase, Kenichi Kashima, Atsushi Kanno, Kouichi Akahane, Atsushi Matsumoto, Naokatsu Yamamoto, Tetsuya Kawanishi
100 GHz optical-to-radio converter module and its application in radio and power over fiber transmission through multi-core fiber. OFC (2017)
Toshimasa Umezawa, Tadashige Sakamoto, Atsushi Kanno, Ken Kusakata, Kouichi Akahane, Atsushi Matsumoto, Naokatsu Yamamoto, Tetsuya Kawanishi
Dense SDM 32-Pixel 2-D Photodetector Array. ECOC (2017)
Pham Tien Dat, Atsushi Kanno, Toshimasa Umezawa
Advanced Photonic Technologies for Future Mobile Communications and Imaging. SoICT (2017)
Takahide Sakamoto, Toshimasa Umezawa, Guo-Wei Lu, Kouichi Akahane, Atsushi Matsumoto, Atsushi Kanno, Naokatsu Yamamoto, Tetsuya Kawanishi
Spatial Coherent Matched Detection Using High-Speed Two Dimensional Photo-Diode Array for Full-Channel Demultiplexing and Demodulation of Mode-Division-Multiplexed Signals. ECOC (2017)
Toshimasa Umezawa, Kunihisa Jitsuno, Nobuhiko Shibagaki, Atsushi Kanno, Kouichi Akahane, A. Mstsumoto, Naokatsu Yamamoto, Tetsuya Kawanishi
31-GHz single-carrier, 44.6-Gbps photonic wireless transmission using a wide-bandwidth high power photodetector and a pre-distortion technique. OFC (2016)
Naokatsu Yamamoto, Kouichi Akahane, Toshimasa Umezawa, Tetsuya Kawanishi
Monolithically integrated quantum-dot optical modulator with semiconductor optical amplifier for 1.3µm waveband error-free 10-km-long transmission. OFC (2015)
Naokatsu Yamamoto, Kouichi Akahane, Toshimasa Umezawa, Tetsuya Kawanishi
A 1.55-µm Waveband Optical Absorption Characterization of an Electro-Absorption Device with a Highly Stacked InAs/InGaAlAs Quantum Dot Structure. IEICE Trans. Electron. (8) (2015)
Toshimasa Umezawa, Kouichi Akahane, Naokatsu Yamamoto, Atsushi Kanno, Tetsuya Kawanishi
Bias free operational 107-Gbaud ultra-fast photodetector. ECOC (2015)
Toshimasa Umezawa, Kouichi Akahane, Naokatsu Yamamoto, Atsushi Kanno, Keizo Inagaki, Tetsuya Kawanishi
Zero-bias operational ultra-broadband UTC-PD above 110 GHz for high symbol rate PD-array in high-density photonic integration. OFC (2015)
Kouichi Akahane, Naokatsu Yamamoto, Atsushi Kanno, Toshimasa Umezawa, Tetsuya Kawanishi
Quantum dot two-mode laser at 1.55 μm-band for 90GHz radio over fiber applications. ECOC (2014)
Tetsuya Kawanishi, Naokatsu Yamamoto, Toshimasa Umezawa, Kouichi Akahane, Atsushi Kanno, Pham Tien Dat
Electro-optic devices for imaging systems using radio-over-fibre. ICTON (2014)