Polarization-insensitive and compact single-mode filter on a 340 nm silicon-on-insulator platform

Opt Lett. 2025 Jan 15;50(2):357-360. doi: 10.1364/OL.543732.

Abstract

In this paper, we propose and demonstrate an integrated polarization-insensitive single-mode filter (SMF) on a 340 nm silicon-on-insulator (SOI) platform, by introducing two lateral coupling waveguides to couple high-order modes from central single-mode waveguide to lateral waveguides. The experimental results show that the excess loss is <0.29 dB and the extinction ratio is >20 dB with a broad bandwidth of 136 nm for the fabricated SMF with a compact footprint of <13 µm.