Large mode volume integrated Brillouin lasers for scalable ultra-Low linewidth and high power

TL;DR

This paper introduces an integrated Brillouin laser with a record-low 31 mHz linewidth, high power, and tunability, achieved through a large mode volume silicon nitride resonator, promising advancements in quantum sensing and precision applications.

Contribution

The paper presents a novel integrated laser design utilizing large mode volume silicon nitride resonators to achieve ultra-low linewidths and high power, surpassing previous limitations.

Findings

Achieved a 31 mHz instantaneous linewidth, the lowest reported.

Demonstrated 41 mW output power with 73 dB side-mode suppression.

Tuned the laser across a 22.5 nm wavelength range.

Abstract

Generating ultra-low linewidths and high output power in an integrated single mode laser remains a critical challenge for future compact, portable, precision applications. Moreso, achieving these characteristics in a laser design that enables scaling to lower linewidths and higher power, and implementation in a wafer-scale integration platform that can operate from visible to near-IR and be integrated with other components. Such an advance could impact a wide array of applications including atomic and quantum sensing and computing, metrology, coherent fiber communications and sensing, and ultra-low-noise mmWave and RF generation. Yet, achieving these goals in an integrated laser has remained elusive. Here, we report a class of integrated laser that overcomes these limitations, with demonstration of a 31 mHz instantaneous linewidth, the lowest linewidth to date to the best of our knowledge, with 41 mW output power and 73 dB sidemode suppression ratio and can be tuned across a 22.5 nm range. This performance is possible due to Brillouin nonlinear dynamics that occurs within a large mode volume, nonlinear photon-phonon, MHz-scale-FSR, ultra-low loss silicon nitride resonator cavity. This laser design can scale to a new operating regime of mHz fundamental linewidth and Watt class lasers. Such lasers hold promise to unlock new sensitivity and fidelity for precision quantum experiments, portable precision applications, and atomic, molecular, and optical physics.