Apodized and un-apodized sidewall grating filters with low coupling constants in ultra-low-loss Si3N4 planar waveguides

Abstract

We demonstrate apodized and un-apodized sidewall grating filters in an ultra-low-loss planar Si₃N₄ integration platform. Record low coupling constants, as low as 0.19 cm^-1, and better than 5dB side-lobe suppression with apodization are reported.