# Compact polarization-independent non-volatile optical switches

## TL;DR

This paper introduces a compact, polarization-independent non-volatile optical switch on silicon using Sb2S3 PCM, enabling efficient, reconfigurable photonic circuits with minimal crosstalk and loss.

## Contribution

It presents a novel design of a polarization-independent, non-volatile optical switch utilizing Sb2S3 PCM integrated into a multimode slot waveguide.

## Key findings

- Crosstalk less than -21.9 dB at 1550 nm
- Insertion loss below 0.12 dB at 1550 nm
- Achieves polarization independence through optimized waveguide design

## Abstract

Compact, non-volatile optical switches on silicon platforms are essential for reconfigurable photonics, but the strong anisotropy of silicon waveguides leads to polarization-dependent performance. In this paper, we propose a polarization-independent, non-volatile optical switch utilizing low-loss phase change material (PCM) Sb2S3. By incorporating Sb2S3 into a multimode slot waveguide, multimode interference can be efficiently tuned for both TE and TM polarizations, owing to enhanced light-PCM interaction. Polarization-independent switching is achieved through the optimal design of the multimode slot waveguide region. The proposed non-volatile switch demonstrates a crosstalk (CT) < -21.9 dB and insertion loss (IL) < 0.12 dB at 1550 nm with a multimode section length of 9.67 {\mu}m, which may find promising applications in reconfigurable photonic circuits for on-chip optical signal processing.

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Source: https://tomesphere.com/paper/2508.20490