Narrow linewidth Brillouin laser based on chalcogenide photonic chip

TL;DR

This paper demonstrates a novel narrow linewidth Brillouin laser on a chalcogenide chip, achieving low threshold, high efficiency, and ultra-narrow linewidth, advancing integrated photonic laser technology.

Contribution

It introduces the first waveguide-based Brillouin laser on a chalcogenide chip with low threshold and narrow linewidth, enabled by large Brillouin gain and optical feedback.

Findings

Lasing threshold of 360 mW, five times lower than single-pass threshold

Laser linewidth of 100 kHz measured with self-heterodyne method

Slope efficiency of 30%

Abstract

We present the first demonstration of a narrow linewidth, waveguide-based Brillouin laser which is enabled by large Brillouin gain of a chalcogenide chip. The waveguides are equipped with vertical tapers for low loss coupling. Due to optical feedback for the Stokes wave, the lasing threshold is reduced to 360 mW, which is 5 times lower than the calculated single-pass Brillouin threshold for the same waveguide. The slope efficiency of the laser is found to be 30% and the linewidth of 100 kHz is measured using a self-heterodyne method.