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)