A TE-TM mode splitter in LiNbO/sub 3/ by proton exchange and Ti diffusion

Abstract

A TE-TM mode splitter using branching waveguides made by proton exchange (PE) and Ti indiffusion (TI) in Z-cut LiNbO/sub 3/ is proposed and designed using the coupled mode theory. The TE-TM mode splitting was experimentally verified, and extinction ratios of 20 dB and more than 20 dB were successfully achieved for TM and TE modes, respectively. The effective index of the PE waveguide was controlled through the PE and postannealing time at fixed temperatures. An equivalent device for two-way communication is suggested and discussed theoretically.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>