Off resonance laser frequency stabilization using the Faraday effect

TL;DR

This paper introduces a straightforward method for stabilizing laser frequency far from resonance by exploiting the Faraday effect in a heated vapor cell with a magnetic field, enabling stable locking at large detunings.

Contribution

The authors demonstrate a simple off-resonance laser stabilization technique using the Faraday effect, adjustable via temperature and magnetic field, effective up to 14 GHz detuning.

Findings

Achieved laser frequency stabilization up to 14 GHz detuned from atomic resonance.

Maintained an rms fluctuation of 16 MHz over one hour without temperature or magnetic field stabilization.

Method is simple and effective for off-resonance laser locking.

Abstract

We present a simple technique for stabilization of a laser frequency off resonance using the Faraday effect in a heated vapor cell with an applied magnetic field. In particular we demonstrate stabilization of a 780 nm laser detuned up to 14 GHz from the 85Rb D2 5 2S_1/2 F = 2 to 5 2P_3/2 F' = 3 transition. Control of the temperature of the vapor cell and the magnitude of the applied magnetic field allows locking ~6-14 GHz red and blue detuned from the atomic line. We obtain an rms fluctuation of 16(1) MHz over one hour without stabilization of the cell temperature or magnetic field.