InP-Based Photodetectors Monolithically Integrated with 90° Hybrid toward Over 400Gb/s Coherent Transmission Systems. - Hideki Yagi; Takuya Okimoto; Naoko Inoue; Koji Ebihara; Kenji Sakurai; Munetaka Kurokawa; Satoru Okamoto; Kazuhiko Horino; Tatsuya Takeuchi; Kouichiro Yamazaki; Yoshifumi Nishimoto; Yasuo Yamasaki; et al. (IEICE Trans. Electron., 2019)