Mach-Zehnder Optical Modulator Integrated with Tunable Multimode Interference Coupler of Ti:LiNbO3 Waveguides for Controlling Modulation Extinction Ratio. - Anna Hirai; Yuichi Matsumoto; Takanori Sato; Tadashi Kawai; Akira Enokihara; Shinya Nakajima; Atsushi Kanno; Naokatsu Yamamoto (IEICE Trans. Electron., 2022)