# Noise investigation of a dual-frequency VECSEL for application to Cesium clocks

## TL;DR

This study combines theoretical and experimental approaches to analyze the noise characteristics of a dual-frequency VECSEL at Cesium clock wavelength, aiming to improve laser stability for atomic clock applications.

## Contribution

It provides a comprehensive noise analysis of a dual-frequency VECSEL, including intensity and phase noise, with a validated theoretical model that guides noise reduction strategies.

## Key findings

- Intensity noises are accurately predicted by coupled rate equations.
- Phase noise is explained by thermal effects and phase-amplitude coupling.
- Good agreement between theory and experiment suggests pathways to reduce laser noise.

## Abstract

We theoretically and experimentally study the noise of a class-A dual-frequency vertical external cavity surface emitting laser operating at Cesium clock wavelength. The intensity noises of the two orthogonally polarized modes and the phase noise of their beatnote are investigated. The intensity noises of the two modes and their correlations are well predicted by a theory based on coupled rate equations. The phase noise of the beatnote is well described by considering both thermal effects and the effect of phase-amplitude coupling. The good agreement between theory and experiment indicates possible ways to further decrease the laser noises.