Two-beam nonlinear Kerr effect to stabilize laser frequency with sub-Doppler resolution

TL;DR

This paper introduces a simple, robust two-beam nonlinear Kerr effect method for stabilizing laser frequency with sub-Doppler resolution, avoiding the need for modulation or magnetic fields.

Contribution

It presents a novel two-beam technique leveraging nonlinear atomic vapor properties to generate sub-Doppler dispersive signals for laser locking.

Findings

Achieved stable laser frequency locking using the proposed method.

Demonstrated sub-Doppler resolution without modulation or magnetic fields.

Showed robustness and simplicity of the technique in atomic physics experiments.

Abstract

Avoiding laser frequency drifts is a key issue in many atomic physics experiments. Several techniques have been developed to lock the laser frequency using sub-Doppler dispersive atomic lineshapes as error signals in a feedback loop. We propose here a two-beam technique that uses non-linear properties of an atomic vapor around sharp resonances to produce sub-Doppler dispersive-like lineshapes that can be used as error signals. Our simple and robust technique has the advantage of not needing either modulation or magnetic fields.