A corner-cube-feedback Faraday laser with 8 kHz linewidth

TL;DR

This paper demonstrates a robust, narrow-linewidth Faraday laser at 852 nm using corner-cube feedback, achieving an 8 kHz linewidth suitable for quantum precision measurements like atomic clocks and magnetometers.

Contribution

It introduces a novel corner-cube feedback mechanism in a Faraday laser, significantly enhancing mechanical stability while maintaining a narrow linewidth.

Findings

Achieved 8 kHz linewidth in the Faraday laser.

Maintained frequency stability across diode current and temperature variations.

Demonstrated wide-angle oscillation capability from +3° to -3°.

Abstract

A single-mode Cs atom 852 nm Faraday laser based on the corner cube feedback is demonstrated, and termed as corner-cube-feedback Faraday laser. Using the corner-cube retroreflector as external cavity feedback element in Faraday laser, mechanical robustness can be greatly improved due to the precise reflection of the incident light beam back to its original direction. This Faraday laser can achieve laser oscillation at a large angle, which between the incident light and the optical axis of corner cube, ranging from +3{\deg} to -3{\deg}. The most probable linewidth is 8 kHz measured by heterodyne beating with two identical lasers. Moreover, its output frequency remains close to the Cs atomic Doppler-broadened transition line, even though the diode current changes from 55 mA to 155 mA and the diode working temperature varies from 11.8 to 37.2 degrees Celsius. The corner-cube-feedback Faraday laser with high mechanical robustness as well as narrow linewidth can be widely used in quantum precision measurement, such as atomic clocks, atomic gravimeters, and atomic magnetometers, etc.