Thin-Film Optical-Waveguide Mode Converters Using Gyrotropic and Anisotropic Substrates

Abstract

Here we report a computer study of mode conversion in thin-film optical waveguides using gyrotropic YIG or anisotropic LiNbO3 as the substrate material. The computational results confirm that complete mode conversion from TE to TM or vice versa can be achieved if the mode converter is operated degenerately for both the TE and TM modes. Further, the length of the optical waveguide and the tolerances on the incident angle and film thickness indicate that the device is feasible.