Transmitter-Receiver Optical Sub Assembly using Ultra-Compact Tunable DBR/Ring Laser. - Kazuya Nagashima; Yozo Ishikawa; Atsushi Izawa; Masayoshi Nishita; Noritaka Matsubara; Hiroyuki Ishii; Thanakit Saeyang; Yoshihiro Ogiso; Yuta Ueda; Masaki Kohtoku (OFC, 2021)