Novel Functionality and Material for Si-Photonics: Two-Photon Absorption Switching and Antimonide Hetero-Genius Epitaxy. - Tak-Keung Liang; Kouichi Akahane; Naokatsu Yamamoto; Luis Romeu Nunes; Tetsuya Kawanishi; Masahiro Tsuchiya (IEICE Trans. Electron., 2007)

Experimental study on the condition of the formation of electric field domains in multiple finite-superlattices. - Naoki Ohtani; S. Noma; Kouichi Akahane; M. Hosoda; K. Fujita (Microelectron. J., 2009)

Skew Dependence of Nanophotonic Devices Based on Optical Near-Field Interactions. - Makoto Naruse; Ferdinand Peper; Kouichi Akahane; Naokatsu Yamamoto; Tadashi Kawazoe; Naoya Tate; Motoichi Ohtsu (ACM J. Emerg. Technol. Comput. Syst., 2012)

10-GHz High-Repetition Optical Short Pulse Generation from Wavelength-Tunable Quantum Dot Optical Frequency Comb Laser. - Naokatsu Yamamoto; Kouichi Akahane; Tetsuya Kawanishi; Hideyuki Sotobayashi; Yuki Yoshioka; Hiroshi Takai (IEICE Trans. Electron., 2013)

Quantum dot two-mode laser at 1.55 μm-band for 90GHz radio over fiber applications. - Kouichi Akahane; Naokatsu Yamamoto; Atsushi Kanno; Toshimasa Umezawa; Tetsuya Kawanishi (ECOC, 2014)

Electro-optic devices for imaging systems using radio-over-fibre. - Tetsuya Kawanishi; Naokatsu Yamamoto; Toshimasa Umezawa; Kouichi Akahane; Atsushi Kanno; Pham Tien Dat (ICTON, 2014)

Bias free operational 107-Gbaud ultra-fast photodetector. - Toshimasa Umezawa; Kouichi Akahane; Naokatsu Yamamoto; Atsushi Kanno; Tetsuya Kawanishi (ECOC, 2015)

Zero-bias operational ultra-broadband UTC-PD above 110 GHz for high symbol rate PD-array in high-density photonic integration. - Toshimasa Umezawa; Kouichi Akahane; Naokatsu Yamamoto; Atsushi Kanno; Keizo Inagaki; Tetsuya Kawanishi (OFC, 2015)

Multifunctional all-optical signal processing scheme for simultaneous multichannel WDM multicast and XOR logic gates based on FWM in QD-SOA. - Danshi Wang; Min Zhang 016; Guo-Wei Lu; Jun Qin; Takahide Sakamoto; Kouichi Akahane; Naokatsu Yamamoto; Tetsuya Kawanishi; Ze Li 007; Yue Cui (OFC, 2015)

Monolithically integrated quantum-dot optical modulator with semiconductor optical amplifier for 1.3µm waveband error-free 10-km-long transmission. - Naokatsu Yamamoto; Kouichi Akahane; Toshimasa Umezawa; Tetsuya Kawanishi (OFC, 2015)

A 1.55-µm Waveband Optical Absorption Characterization of an Electro-Absorption Device with a Highly Stacked InAs/InGaAlAs Quantum Dot Structure. - Naokatsu Yamamoto; Kouichi Akahane; Toshimasa Umezawa; Tetsuya Kawanishi (IEICE Trans. Electron., 2015)

31-GHz single-carrier, 44.6-Gbps photonic wireless transmission using a wide-bandwidth high power photodetector and a pre-distortion technique. - Toshimasa Umezawa; Kunihisa Jitsuno; Nobuhiko Shibagaki; Atsushi Kanno; Kouichi Akahane; A. Mstsumoto; Naokatsu Yamamoto; Tetsuya Kawanishi (OFC, 2016)

Spatial Coherent Matched Detection Using High-Speed Two Dimensional Photo-Diode Array for Full-Channel Demultiplexing and Demodulation of Mode-Division-Multiplexed Signals. - Takahide Sakamoto; Toshimasa Umezawa; Guo-Wei Lu; Kouichi Akahane; Atsushi Matsumoto; Atsushi Kanno; Naokatsu Yamamoto; Tetsuya Kawanishi (ECOC, 2017)

Dense SDM 32-Pixel 2-D Photodetector Array. - Toshimasa Umezawa; Tadashige Sakamoto; Atsushi Kanno; Ken Kusakata; Kouichi Akahane; Atsushi Matsumoto; Naokatsu Yamamoto; Tetsuya Kawanishi (ECOC, 2017)

100 GHz optical-to-radio converter module and its application in radio and power over fiber transmission through multi-core fiber. - Toshimasa Umezawa; Pham Tien Dat; Eiichi Hase; Kenichi Kashima; Atsushi Kanno; Kouichi Akahane; Atsushi Matsumoto; Naokatsu Yamamoto; Tetsuya Kawanishi (OFC, 2017)

High-speed Two-dimensional Photodetector Array for 4-WDM 25-Gbaud FSO Communication. - Toshimasa Umezawa; Takahide Sakamoto; Atsushi Kanno; Kouichi Akahane; Atsushi Matsumoto; Naokatsu Yamamoto; Tetsuya Kawanishi (OFC, 2018)

400-pixel high-speed photodetector for high optical alignment robustness FSO receiver. - Toshimasa Umezawa; Atsushi Matsumoto; Kouichi Akahane; Atsushi Kanno; Naokatsu Yamamoto (OFC, 2022)

Photonic Approach to Reinforcement Learning. - Makoto Naruse; Atsushi Uchida; Kazuharu Uchiyama; Kouichi Akahane (OECC/PSC, 2022)

60-Gb/s D-Band Wireless Signal Generation and Transmission Using Photonic Technology. - Pham Tien Dat; Keizo Inagaki; Atsushi Kanno; Kouichi Akahane (RIVF, 2022)

Admittance Spectroscopy Up to 67 GHz in InGaAs/InAlAs Triple-Barrier Resonant Tunneling Diodes. - Kotaro Aikawa; Michihiko Suhara; Takumi Kimura; Junki Wakayama; Takeshi Makino; Katsuhiro Usui; Kiyoto Asakawa; Kouichi Akahane; Issei Watanabe (IEICE Trans. Electron., 2022)

Transparent Relay and Switching of THz-wave Signals in 285-GHz Band Using Photonic Technology. - Pham Tien Dat; Yuya Yamaguchi; Keizo Inagaki; Shingo Takano; Shotaro Hirata; Junichiro Ichikawa; Ryo Shimizu; Isao Morohashi; Yuki Yoshida; Atsushi Kanno; Naokatsu Yamamoto; Tetsuya Kawanishi; et al. (OFC, 2023)

Transparent Radio-Fiber-Radio-Fiber System in 100-GHz Band for Indoor Uplink Signal Transmission in Beyond 5G. - Pham Tien Dat; Yuya Yamaguchi; Atsushi Kanno; Naokatsu Yamamoto; Tetsuya Kawanishi; Kouichi Akahane (OFC, 2023)

100-Gbps 2-SDM 2-WDM FSO beam direct detection using resonant cavity 4x4 photodetector array. - Toshimasa Umezawa; Atsushi Matsumoto; Kouichi Akahane; Atsushi Kanno; Naokatsu Yamamoto (OFC, 2023)

Delay Compensated Quad-level Delta-sigma Modulation Dual-color DRoF System for Beyond 5G Mobile Fronthaul. - Zu-Kai Weng; Pham Tien Dat; Atsushi Kanno; Tetsuya Kawanishi; Kouichi Akahane (OFC, 2023)

Dispersion Compensation over C-band WDM Grid for 100Gb/s PAM4 System by Low-complexity Optoelectronic Feedforward Equalization (OE-FFE). - Paikun Zhu; Yuki Yoshida; Atsushi Kanno; Kouichi Akahane; Ken-ichi Kitayama (OFC, 2023)

DSP-enhanced Radio-over-fiber Xhaul Networks Toward Beyond-5G. - Paikun Zhu; Yuki Yoshida; Atsushi Kanno; Kouichi Akahane; Ken-ichi Kitayama (OFC, 2023)

Radio-Over-X (RoX) Technologies for Future Local Access Network. - Toshiaki Kuri; Pham Tien Dat; Kouichi Akahane (ICC Workshops, 2024)

5G NR Signal Transparent Transmission Over a Converged Fiber-THz-Fiber-mmWave System. - Pham Tien Dat; Yuya Yamaguchi; Keizo Inagaki; Kouichi Akahane (INFOCOM (Workshops), 2024)

Enabling Fiber-Wireless Technologies For Radio Communications In Millimeter-Wave and Terahertz-Wave Bands In IMT-2030 and Beyond. - Pham Tien Dat; Yuya Yamaguchi; Kouichi Akahane (ITU K, 2024)

Low-Divergent 940-nm Photonic-Crystal Surface-Emitting Laser for Short-Reach Free-Space Data Link. - Chih-Hsien Cheng; Po-Lun Chen; Pin-Wei Ho; Yu-Heng Hong; Shih-Chen Chen; Shu-Wei Chang; Chao-Hsin Wu; Hao-Chung Kuo; Atsushi Matsumoto; Kouichi Akahane; Gong-Ru Lin (OFC, 2024)

151.5-GHz Sub-THz Signal Reception and Downconversion Using All-Optical Technology. - Pham Tien Dat; Yuya Yamaguchi; Shingo Takano; Shotaro Hirata; Junichiro Ichikawa; Ryo Shimizu; Keizo Inagaki; Isao Morohashi; Yuki Yoshida; Atsushi Kanno; Naokatsu Yamamoto; Kouichi Akahane (OFC, 2024)

All-in-one TO-can-Packed RGB-LD Lamp Enables 40-Gbit/s White-lighting Wireless DMT Link. - Gong-Ru Lin; Chih-Hsien Cheng; Po-Lun Chen; Pin-Wei Ho; Szu-En Lai; Yi-Chien Wu; Yu-Sheng Liao; Yu-Chieh Chi; Atsushi Matsumoto; Kouichi Akahane (OFC, 2024)

DC-226 GHz well-impedance-matched high-speed photoreceiver for multi-band signal detection. - Toshimasa Umezawa; Pham Tien Dat; Yuki Yoshida; Shinya Nakajima; Atsushi Matsumoto; Kouichi Akahane; Atsushi Kanno; Naokatsu Yamamoto (OFC, 2024)

Demonstration of Robust Mobile Free Space Optical System using High-speed Beam Tracking and 2D-PDA-based Spatial-Diversity Reception. - Zu-Kai Weng; Yuki Yoshida; Toshimasa Umezawa; Abdelmoula Bekkali; Michikazu Hattori; Atsushi Matsumoto; Atsushi Kanno; Naokatsu Yamamoto; Tetsuya Kawanishi; Kouichi Akahane (OFC, 2024)

40-Gbit/s Mobile FSO with High-speed Beam Stabilizer and 2D-PDA-based Diversity Receiver for Support Robots. - Zu-Kai Weng; Yuki Yoshida; Toshimasa Umezawa; Abdelmoula Bekkali; Michikazu Hattori; Atsushi Matsumoto; Atsushi Kanno; Naokatsu Yamamoto; Tetsuya Kawanishi; Kouichi Akahane (OFC, 2024)

Thin-Film Lithium Niobate Modulator for a Flat Frequency-Response over 110 GHz Bandwidth with Integrated Electro-Optic Frequency-Domain Equalizer. - Yuya Yamaguchi; Pham Tien Dat; Naokatsu Yamamoto; Kouichi Akahane; Atsushi Kanno; Tetsuya Kawanishi (OFC, 2024)

Reach Extension of Net-200G/λ IM-DD PAM4 Links to Beyond-100km with Low-complexity Using OE-EQ. - Paikun Zhu; Yuki Yoshida; Kouichi Akahane; Ken-ichi Kitayama (OFC, 2024)

High-Responsivity Unitraveling Carrier-Type Photodetector Using Avalanche InAlAs as a Collector at a High-Frequency Range. - Yaofeng Yi; Toshimasa Umezawa; Kouichi Akahane; Tetsuya Kawanishi (IEEE Access, 2024)

Thermal Study for High-Photocurrent Photodetector in Non-Saturation Region Using Thin Substrate, Thin Absorber, and Flip- Chip Bonding Process. - Yaofeng Yi; Toshimasa Umezawa; Kouichi Akahane; Tetsuya Kawanishi (IEEE Access, 2024)

Optical Mode Multiplexer Using LiNbO3 Asymmetric Directional Coupler Enabling Voltage Control for Phase-Matching Condition. - Shotaro Yasumori; Seiya Morikawa; Takanori Sato; Tadashi Kawai; Akira Enokihara; Shinya Nakajima; Kouichi Akahane (IEICE Trans. Electron., 2024)

High-speed reach-extended IM-DD system with low-complexity DSP for 6G fronthaul [Invited]. - Paikun Zhu; Yuki Yoshida; Kouichi Akahane; Ken-ichi Kitayama (J. Opt. Commun. Netw., 2024)

Sub-Terahertz Signal Demultiplexing and Downconversion Using Photonic Technology. - Pham Tien Dat; Yuya Yamaguchi; Yuki Yoshida; Atsushi Kanno; Naokatsu Yamamoto; Tetsuya Kawanishi; Kouichi Akahane (OFC, 2025)

International Testbed Data Sharing Framework with Data Sovereign Features for Network AI/ML Empowerment. - Yusuke Hirota; Sugang Xu; Angela Mitrovska; Yuki Yoshida; Pooyan Safari; Behnam Shariati; Johannes K. Fischer; Ronald Freund; Hideaki Furukawa; Kouichi Akahane; Yoshinari Awaji (OFC, 2025)

Fully Packaged 100-GHz-Bandwidth EO-Equalizer-Integrated TFLN Modulator with Record-High Slope Efficiency Enabling 200-GBaud Signaling. - Yuya Yamaguchi; Paikun Zhu; Pham Tien Dat; Shingo Takano; Shotaro Hirata; Yu Kataoka; Junichiro Ichikawa; Ryo Shimizu; Kouichi Akahane; Naokatsu Yamamoto; Atsushi Kanno; Tetsuya Kawanishi (OFC, 2025)

Low-Complexity Digital Twinning of Optical I/Q Modulator by Direct-Detection with Widely Non-Linear Phase Retrieval. - Yuki Yoshida; Shoichiro Oda; Naokatsu Yamamoto; Takeshi Hoshida; Kouichi Akahane (OFC, 2025)

Pairwise Transmission Enabling Dispersion-unconstrained Multilane IM-DD Systems Beyond 100G-per-lane. - Paikun Zhu; Yuki Yoshida; Kouichi Akahane; Ken-ichi Kitayama; Bahram Jalali (OFC, 2025)