Single polarization waveguide based on thin film lithium niobate

Here we demonstrated a single polarization waveguide and spot size converter for edge coupling working at O band based on Lithium niobate on insulator.The improvement extinction ratio of 35dB/cm is obtained for the single polarization waveguides. The insertion loss of bilayer spot size converters is 3.5dB/facet from our best results at the light length of 1310nm.