# Stabilization of a laser on a large-detuned atomic-reference frequency by resonant interferometry

## TL;DR

This paper introduces a straightforward method for stabilizing laser frequency at large detunings from atomic resonance using resonant interferometry in a low-quality cavity filled with atomic vapor, achieving high stability without complex setups.

## Contribution

The authors demonstrate a simple, modulation-free technique for laser stabilization at large detunings using interference effects in atomic vapor, expanding the tools for laser frequency control.

## Key findings

- Achieved a fractional frequency Allan deviation of 10^{-8} at 300 s
- Successfully locked laser at detunings larger than 10 GHz
- Method does not require magnetic fields or signal modulation

## Abstract

We report a simple technique for stabilization of a laser frequency at the wings of an atomic resonance. The reference signal used for stabilization issues from interference effects obtained in a low-quality cavity filled with a resonant atomic vapour. For a frequency detuned at 2.6 GHz from the $^{133}$Cs D$_2$ 6S$_{1/2}$ F=4 to 6P$_{3/2}$ F'= 5 transition, the fractional frequency Allan deviation is $10^{-8}$ for averaging times of 300 s, corresponding to a frequency deviation of 4 MHz. Adequate choice of the atomic density and of the cell thickness allows locking the laser at detunings larger than 10 GHz. Such a simple technique does not require magnetic fields or signal modulation.