Extreme Linewidth Narrowing in Diamond Raman Lasers Enables the Generation of 35 W at 589 nm with Hz-Scale Intrinsic Linewidth

TL;DR

This paper demonstrates a high-power diamond Raman laser emitting 35 W at 589 nm with an ultra-narrow linewidth of 6 Hz, suitable for quantum and space technologies.

Contribution

The work achieves record efficiency and extreme linewidth narrowing in diamond Raman lasers, enabling stable, high-power, single-frequency visible light sources.

Findings

Generated 35 W at 589 nm with 47.7% efficiency.

Achieved a measurement-limited linewidth of 6 Hz.

Enabled stabilization to sodium D2a transition.

Abstract

High-power lasers with narrow linewidth and high beam quality in the visible spectrum are essential for emerging quantum and space technologies. Here we report significant advances in diamond Raman lasers, generating diffraction-limited yellow light at 589 nm with output power up to 35 W and enhanced single-frequency stability. The optical-to-optical efficiency from the pump reaches 47.7%, representing a record efficiency for this class of devices. More importantly, the extreme linewidth-narrowing of Raman lasing in diamond enables a reduction in frequency noise exceeding six orders of magnitude, resulting in a measurement-limited intrinsic linewidth of 6 Hz at the maximum power. The laser is further stabilized to the sodium D2a saturation-absorption transition, making it well-suited for sodium-based space and quantum experiments. These results represent a major step toward continuous-wave, high-power, single-frequency laser sources across the visible spectrum that combine ultranarrow linewidth, high efficiency, and near-diffraction-limited beam quality for advanced quantum and space applications.