A laser setup for rubidium cooling dedicated to space applications

TL;DR

This paper details a space-compatible rubidium cooling laser system using fiber components, frequency doubling, and stabilization techniques, with comprehensive characterization including stability, noise, and environmental testing.

Contribution

It introduces a fully characterized, space-ready laser setup for rubidium cooling based on commercial fiber components and innovative frequency control methods.

Findings

Achieved stable optical frequencies suitable for space applications.

Demonstrated environmental robustness of the frequency doubling module.

Provided detailed frequency stability and noise measurements.

Abstract

We present the complete characterization of a laser setup for rubidium cooling dedicated to space applications. The experimental setup is realized with commercial off-the-shelf fiber components suitable for space applications. By frequency doubling two fiber laser diodes at 1560 nm, we produce the two optical frequencies at 780 nm required for atomic cooling of $^{87}$Rb. The first laser is locked on saturated absorption signal and long term frequency drift has been canceled using a digital integrator. The optical frequency of the second laser is controlled relatively to the first one by a frequency comparison method. A full characterization of the setup, including frequency stability evaluation and frequency noise measurement has been performed. The optical frequency doubling module has been submitted to environmental tests to verify its compatibility with space applications.