Large Brillouin Amplification in Silicon

TL;DR

This paper reports the first large Brillouin amplification in silicon using a novel membrane-suspended waveguide, achieving over 5 dB gain at low pump power, advancing silicon-based optomechanical devices.

Contribution

Introduction of a membrane-suspended silicon waveguide enabling significant Brillouin amplification with a record low threshold power.

Findings

Achieved over 5 dB Brillouin gain in silicon.

Demonstrated a 5 mW threshold for net amplification.

Enabled potential for high-performance silicon Brillouin lasers.

Abstract

Strong Brillouin coupling has only recently been realized in silicon using a new class of optomechanical waveguides that yield both optical and phononic confinement. Despite these major advances, appreciable Brillouin amplification has yet to be observed in silicon. Using a new membrane-suspended silicon waveguide we report large Brillouin amplification for the first time, reaching levels greater than 5 dB for modest pump powers, and demonstrate a record low (5 mW) threshold for net amplification. This work represents a crucial advance necessary to realize high-performance Brillouin lasers and amplifiers in silicon.