Compact Tunable DBR/Ring Laser Module Integrated with Extremely-high-Δ PLC Wavelength Locker. - Masayoshi Nishita; Yasutaka Higa; Noritaka Matsubara; Junichi Hasegawa; Kazuki Yamaoka; Maiko Ariga; Yusuke Inaba; Masayoshi Kimura; Masaki Wakaba; Masahiro Yoshida; Kazuomi Maruyama; Shunsuke Okuyama; et al. (OFC, 2020)