Toshimasa Umezawa

40 papers Journal 3Unranked 37

Year	Rank	Type	Title / Venue / Authors
2025	—	`conf`	$150-\text{GHz}$ Bandwidth, -30 dB CMRR Balanced Photodetector for High-Baud Rate PSK Signal Detection. ECOC Toshimasa Umezawa, Shinya Nakajima, Atsushi Matsumoto, Kouichi Akahane, Naokatsu Yamamoto
2025	—	`conf`	16 A/W, DC-200 GHz Ultra-Broadband Photoreceiver Module for High Baud Rate Small Signal Detection. OFC Toshimasa Umezawa, S. Nakajima, A. Matsumoto, Koichi Akahane, Atsushi Kanno, N. Yamamoto
2025	—	`conf`	Demonstration of Photodetector-Array-Based Reconfigurable Mode-Division-Multiplexing Coherent Receiver for Spatial Modes Varying Two Indices. ECOC Zile Jiang, Xinzhou Su, Huibin Zhou, Abdulrahman Alhaddad, Muralekrishnan Ramakrishnan, Yuxiang Duan, Toshimasa Umezawa, Yuki Yoshida, Kouichi Akahane, Alan E. Willner
2024	—	`conf`	40-Gbit/s Mobile FSO with High-speed Beam Stabilizer and 2D-PDA-based Diversity Receiver for Support Robots. OFC Zu-Kai Weng, Yuki Yoshida, Toshimasa Umezawa, Abdelmoula Bekkali, Michikazu Hattori, Atsushi Matsumoto, Atsushi Kanno, Naokatsu Yamamoto, Tetsuya Kawanishi, Kouichi Akahane
2024	—	`conf`	DC-226 GHz well-impedance-matched high-speed photoreceiver for multi-band signal detection. OFC Toshimasa Umezawa, Pham Tien Dat, Yuki Yoshida, Shinya Nakajima, Atsushi Matsumoto, Kouichi Akahane, Atsushi Kanno, Naokatsu Yamamoto
2024	—	`conf`	Demonstration of Robust Mobile Free Space Optical System using High-speed Beam Tracking and 2D-PDA-based Spatial-Diversity Reception. OFC Zu-Kai Weng, Yuki Yoshida, Toshimasa Umezawa, Abdelmoula Bekkali, Michikazu Hattori, Atsushi Matsumoto, Atsushi Kanno, Naokatsu Yamamoto, Tetsuya Kawanishi, Kouichi Akahane
2024	J	`jnl`	High-Responsivity Unitraveling Carrier-Type Photodetector Using Avalanche InAlAs as a Collector at a High-Frequency Range. IEEE Access Yaofeng Yi, Toshimasa Umezawa, Kouichi Akahane, Tetsuya Kawanishi
2024	—	`conf`	Low Threshold and 10kHz-Class Narrow Linewidth 1.55 µm-Band Quantum Dot Laser Diode on InP(311)B Substrate. OFC Atsushi Matsumoto, Ryota Yabuki, Shinya Nakajima, Toshimasa Umezawa, Siim Heinsalu, Yuichi Matsushima, Koichi Akahane, Naokatsu Yamamoto, Katsuyuki Utaka
2024	J	`jnl`	Thermal Study for High-Photocurrent Photodetector in Non-Saturation Region Using Thin Substrate, Thin Absorber, and Flip- Chip Bonding Process. IEEE Access Yaofeng Yi, Toshimasa Umezawa, Kouichi Akahane, Tetsuya Kawanishi
2023	—	`conf`	100-Gbps 2-SDM 2-WDM FSO beam direct detection using resonant cavity 4x4 photodetector array. OFC Toshimasa Umezawa, Atsushi Matsumoto, Kouichi Akahane, Atsushi Kanno, Naokatsu Yamamoto
2023	—	`conf`	Self-Coherent Transmission Using Metasurface-based Stokes-Vector Receiver. OFC Go Soma, Yoshiro Nomoto, Toshimasa Umezawa, Yuki Yoshida, Yoshiaki Nakano, Takuo Tanemura
2022	—	`conf`	400-pixel high-speed photodetector for high optical alignment robustness FSO receiver. OFC Toshimasa Umezawa, Atsushi Matsumoto, Kouichi Akahane, Atsushi Kanno, Naokatsu Yamamoto
2022	—	`conf`	50 GHz High Photocurrent PIN-PD and Its Thermal Effect. OECC/PSC Yaofeng Yi, Toshimasa Umezawa, Atsushi Kanno, Tetsuya Kawanishi
2022	—	`conf`	High-Efficient Pixel Layout Arrangement in High-Speed 2-D Photodetector Array. OECC/PSC Siyang Duan, Toshimasa Umezawa, Atsushi Kanno, Tetsuya Kawanishi
2022	—	`conf`	High-Speed Beam Steering LN Optical Phased Array Module using Comb-Electrode. OECC/PSC Hayato Takemura, Haruto Shinya, Yuya Yamaguchi, Toshimasa Umezawa, Atsushi Kanno, Tetsuya Kawanishi
2021	—	`conf`	240-Gbps SDM-FSO communication using 4-bundle fiber and 2D photodetector array. OFC Toshimasa Umezawa, Kunio Jitsuno, Naokatsu Yamamoto, Tetsuya Kawanishi
2021	—	`conf`	Submillimeter Large High-speed Photodetector for High Optical Alignment Robustness Optical Wireless Communications. ECOC Toshimasa Umezawa, Shinya Nakajima, Atsushi Kanno, Naokatsu Yamamoto
2020	—	`conf`	30 GHz Radio over FSO System using High Speed 2D-PDA and Its Optical Path Switching Performance. ECOC Toshimasa Umezawa, Pham Tien Dat, Atsushi Kanno, Kunihisa Jitsuno, Naokatsu Yamamoto, Tetsuya Kawanishi
2020	—	`conf`	High Speed 2D-PDA FSO Receiver for High Optical Alignment Robustness with Space Diversity. OFC Toshimasa Umezawa, Yuki Yoshida, Atsushi Kanno, Naokatsu Yamamoto, Tetsuya Kawanishi
2020	—	`conf`	On the Sample Complexity of Phase-Retrieval Receiver Based on 2-D Arrayed Photodetectors. OFC Yuki Yoshida, Toshimasa Umezawa, Atsushi Kanno, Keizo Inagaki, Naokatsu Yamamoto, Tetsuya Kawanishi
2020	—	`conf`	Phase-Retrieving Coherent Reception and its Sample Complexity. ECOC Yuki Yoshida, Toshimasa Umezawa, Atsushi Kanno, Naokatsu Yamamoto
2019	—	`conf`	1-λ, 16-Parallel Lanes, 50-Gbaud On-Off Keying Multi-Core Fiber Communication Directly Coupled to High Speed 2D-Photodetector Array. OFC Toshimasa Umezawa, Atsushi Matsumoto, Atsushi Kanno, Naokatsu Yamamoto, Tetsuya Kawanishi
2019	—	`conf`	Characterization of 2D high-speed photodetector array device for SDM fiber communication applications. OECC/PSC Ken Kusakata, S. Takamizawa, Toshimasa Umezawa, Naokatsu Yamamoto, Tetsuya Kawanishi
2019	—	`conf`	Coherent Detection Only by 2-D Photodetector Array: A Discreteness-Aware Phase Retrieval Approach. OFC Yuki Yoshida, Toshimasa Umezawa, Atsushi Kanno, Naokatsu Yamamoto
2019	—	`conf`	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 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
2019	—	`conf`	Hybrid Optical Wireless-mmWave: Ultra High-Speed Indoor Communications for Beyond 5G. INFOCOM Workshops Pham Tien Dat, Atsushi Kanno, Keizo Inagaki, Toshimasa Umezawa, Naokatsu Yamamoto, Tetsuya Kawanishi
2018	—	`conf`	400-Gbps Space Division Multiplexing Optical Wireless Communication Using Two-Dimensional Photodetector Array. ECOC Toshimasa Umezawa, Takahide Sakamoto, Atsushi Kanno, Shinya Nakajima, Atsushi Matsumoto, Naokatsu Yamamoto, Tetsuya Kawanishi
2018	—	`conf`	High-Speed and Handover-Free Communications for High-Speed Trains Using Switched WDM Fiber-Wireless System. OFC Pham Tien Dat, Atsushi Kanno, Keizo Inagaki, Toshimasa Umezawa, François Rottenberg, Jérôme Louveaux, Naokatsu Yamamoto, Tetsuya Kawanishi
2018	—	`conf`	High-speed Two-dimensional Photodetector Array for 4-WDM 25-Gbaud FSO Communication. OFC Toshimasa Umezawa, Takahide Sakamoto, Atsushi Kanno, Kouichi Akahane, Atsushi Matsumoto, Naokatsu Yamamoto, Tetsuya Kawanishi
2017	—	`conf`	100 GHz optical-to-radio converter module and its application in radio and power over fiber transmission through multi-core fiber. OFC Toshimasa Umezawa, Pham Tien Dat, Eiichi Hase, Kenichi Kashima, Atsushi Kanno, Kouichi Akahane, Atsushi Matsumoto, Naokatsu Yamamoto, Tetsuya Kawanishi
2017	—	`conf`	Advanced Photonic Technologies for Future Mobile Communications and Imaging. SoICT Pham Tien Dat, Atsushi Kanno, Toshimasa Umezawa
2017	—	`conf`	Dense SDM 32-Pixel 2-D Photodetector Array. ECOC Toshimasa Umezawa, Tadashige Sakamoto, Atsushi Kanno, Ken Kusakata, Kouichi Akahane, Atsushi Matsumoto, Naokatsu Yamamoto, Tetsuya Kawanishi
2017	—	`conf`	Spatial Coherent Matched Detection Using High-Speed Two Dimensional Photo-Diode Array for Full-Channel Demultiplexing and Demodulation of Mode-Division-Multiplexed Signals. ECOC Takahide Sakamoto, Toshimasa Umezawa, Guo-Wei Lu, Kouichi Akahane, Atsushi Matsumoto, Atsushi Kanno, Naokatsu Yamamoto, Tetsuya Kawanishi
2016	—	`conf`	31-GHz single-carrier, 44.6-Gbps photonic wireless transmission using a wide-bandwidth high power photodetector and a pre-distortion technique. OFC Toshimasa Umezawa, Kunihisa Jitsuno, Nobuhiko Shibagaki, Atsushi Kanno, Kouichi Akahane, A. Mstsumoto, Naokatsu Yamamoto, Tetsuya Kawanishi
2015	J	`jnl`	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. Naokatsu Yamamoto, Kouichi Akahane, Toshimasa Umezawa, Tetsuya Kawanishi
2015	—	`conf`	Bias free operational 107-Gbaud ultra-fast photodetector. ECOC Toshimasa Umezawa, Kouichi Akahane, Naokatsu Yamamoto, Atsushi Kanno, Tetsuya Kawanishi
2015	—	`conf`	Monolithically integrated quantum-dot optical modulator with semiconductor optical amplifier for 1.3µm waveband error-free 10-km-long transmission. OFC Naokatsu Yamamoto, Kouichi Akahane, Toshimasa Umezawa, Tetsuya Kawanishi
2015	—	`conf`	Zero-bias operational ultra-broadband UTC-PD above 110 GHz for high symbol rate PD-array in high-density photonic integration. OFC Toshimasa Umezawa, Kouichi Akahane, Naokatsu Yamamoto, Atsushi Kanno, Keizo Inagaki, Tetsuya Kawanishi
2014	—	`conf`	Electro-optic devices for imaging systems using radio-over-fibre. ICTON Tetsuya Kawanishi, Naokatsu Yamamoto, Toshimasa Umezawa, Kouichi Akahane, Atsushi Kanno, Pham Tien Dat
2014	—	`conf`	Quantum dot two-mode laser at 1.55 μm-band for 90GHz radio over fiber applications. ECOC Kouichi Akahane, Naokatsu Yamamoto, Atsushi Kanno, Toshimasa Umezawa, Tetsuya Kawanishi