Symmetric Two-Mode Waveguide Directional Coupler on Thin-Film Lithium Niobate for Electro-Optic Mode Switching

Abstract

We design and fabricate a symmetric two-mode waveguide directional coupler on thin-film lithium niobite for electro-optic mode switching. Our experimental device can switch the higher-order mode with an efficiency higher than 65% in the C band with a driving voltage varying from 2.5 V to 20 V.