Large PMD tolerant 1.28 Tbit/s/ch transmission over 525 km with 640 Gbaud optical Nyquist pulses. - Koudai Harako; Peng Ruan; Toshihiko Hirooka; Masataka Nakazawa (OFC/NFOEC, 2013)

Novel ultrafast TDM demultiplexing scheme using orthogonality in coherent Nyquist pulses. - Koudai Harako; David Odeke Otuya; Keisuke Kasai; Toshihiko Hirooka; Masataka Nakazawa (ECOC, 2014)

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. - David Odeke Otuya; Koudai Harako; Keisuke Kasai; Toshihiko Hirooka; Masataka Nakazawa (ECOC, 2014)

All-optical high-performance demultiplexing using optical Nyquist pulse sampling. - Daiki Seya; Koudai Harako; Toshihiko Hirooka; Masataka Nakazawa (OFC, 2014)

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. - David Odeke Otuya; Koudai Harako; Keisuke Kasai; Toshihiko Hirooka; Masataka Nakazawa (OFC, 2015)

A 40 GHz, 770 fs regeneratively mode-locked erbium fiber laser operating at 1.6 µm. - Koudai Harako; Masato Yoshida; Toshihiko Hirooka; Masataka Nakazawa (IEICE Electron. Express, 2017)