Mode conversion analysis in a single-mode planar taper optical waveguide

Abstract

We have investigated mode conversion in a taper waveguide used in a planar multi-branch waveguide optical power divider designed for fundamental mode operation and fabricated by Ti-diffusion into a z-cut LiNbO3 substrate. With an appropriate aspect ratio and index distribution in the taper, mode conversion loss into a higher-order mode can be maintained under 5%.