Structure and method for fabricating a wide-angle TE-TM mode splitter

Abstract

A method is used to fabricate a wide-angle Y-branch polarization splitters on lithium niobate crystal substrate. The Y-branch polarization splitter combines a straight waveguide with a substrate prism type wide-angle waveguide branch. The straight waveguide is a random polarization nickel diffusion waveguide. The branching waveguide is a proton exchanged waveguide. The fabrication technology needs only once of nickel diffusion and once of proton exchange. Due to the inherent property of single polarization for the proton exchanged waveguide, only the extraordinary polarization wave is bent and the ordinary wave remains in the straight waveguide. This results in a polarization splitter with high extinction ratio.

Dependencies are inferred from the claim text.