Compact Brillouin devices through hybrid integration on Silicon

TL;DR

This paper demonstrates a novel silicon-based integrated Brillouin device using As2S3 material, achieving high amplification and lasing, paving the way for compact, manufacturable optical circuits with advanced signal processing capabilities.

Contribution

It introduces a hybrid integration approach with As2S3 on silicon, overcoming nonlinear losses and enabling Brillouin amplification and lasing on a chip for the first time.

Findings

Achieved an order of magnitude increase in Brillouin amplification.

Demonstrated Brillouin lasing in a silicon integrated circuit.

Created a compact spiral and ring resonator device with precise spectral matching.

Abstract

A range of unique capabilities in optical and microwave signal processing have been demonstrated using stimulated Brillouin scattering. The desire to harness Brillouin scattering in mass manufacturable integrated circuits has led to a focus on silicon-based material platforms. Remarkable progress in silicon-based Brillouin waveguides has been made, but results have been hindered by nonlinear losses present at telecommunications wavelengths. Here, we report a new approach to surpass this issue through the integration of a high Brillouin gain material, As2S3, onto a silicon chip. We fabricated a compact spiral device, within a silicon circuit, achieving an order of magnitude improvement in Brillouin amplification. To establish the flexibility of this approach, we fabricated a ring resonator with free spectral range precisely matched to the Brillouin shift, enabling the first demonstration of Brillouin lasing in a silicon integrated circuit. Combining active photonic components with the SBS devices shown here will enable the creation of compact, mass manufacturable optical circuits with enhanced functionality.