Investigations of optical pumping for magnetometry using an auto-locking laser system

TL;DR

This paper introduces a versatile pulsed laser system with auto-locking for high-precision magnetometry, capable of optically pumping rubidium vapors, and demonstrates its suitability for developing portable SERF magnetometers with high sensitivity.

Contribution

The paper presents a novel, auto-locked, interference filter stabilized laser system with pulsing capabilities tailored for high-precision magnetometry applications involving rubidium vapors.

Findings

Laser system successfully stabilizes frequency using an auto-locking controller.

System can amplify laser output from 20 mW to 2 W in CW mode.

Numerical simulations support its effectiveness for rubidium optical pumping.

Abstract

We have developed a versatile pulsed laser system for high precision magnetometry. The operating wavelength of the system can be configured to optically pump alkali vapors such as rubidium and cesium. The laser system consists of an auto-locked, interference filter stabilized, external cavity diode laser (ECDL), a tapered waveguide amplifier, and a pulsing module. The auto-locking controller can be used by an untrained operator to stabilize the laser frequency with respect to a library of atomic, molecular, and solid-state spectral markers. The ECDL output can be amplified from 20 mW to 2 W in continuous wave (CW) mode. The pulsing module, which includes an acousto-optic modulator (AOM), can generate pulses with durations of 20 ns and repetition rates of several MHz. Accordingly, the laser system is well suited for applications such as gravimetry, magnetometry, and differential-absorption lidar. In this work, we focus on magnetometric applications and demonstrate that the laser source is suitable for optically pumping rubidium vapor. We also describe numerical simulations of optical pumping relevant to the rubidium D1 and D2 transitions at 795 nm and 780 nm respectively. These studies are relevant to the design and construction of a new generation of portable, rubidium, spin-exchange relaxation-free (SERF) magnetometers, capable of sensitivities of 1 fT Hz-1/2 1.