Hybrid integrated semiconductor lasers with silicon nitride feedback circuits

TL;DR

This paper reviews hybrid integrated semiconductor lasers with silicon nitride feedback circuits, achieving ultra-narrow linewidths, broad spectral coverage, and high output power, advancing integrated photonic applications.

Contribution

It introduces recent developments in hybrid-integrated diode lasers with silicon nitride feedback, demonstrating sub-100 Hz linewidths, broad spectral coverage, and multi-wavelength functionalities.

Findings

Achieved sub-100 Hz linewidths in hybrid lasers

Demonstrated broad spectral coverage around 1.55 μm

Enabled dual-wavelength and frequency comb operation

Abstract

Hybrid integrated semiconductor laser sources offering extremely narrow spectral linewidth as well as compatibility for embedding into integrated photonic circuits are of high importance for a wide range of applications. We present an overview on our recently developed hybrid-integrated diode lasers with feedback from low-loss silicon nitride (Si3N4 in SiO2) circuits, to provide sub-100-Hz-level intrinsic linewidths, up to 120 nm spectral coverage around 1.55 um wavelength, and an output power above 100 mW. We show dual-wavelength operation, dual-gain operation, laser frequency comb generation, and present work towards realizing a visible-light hybrid integrated diode laser.