Alignment-based optically pumped magnetometer using a buffer gas cell

TL;DR

This paper demonstrates a novel alignment-based optically pumped magnetometer using a buffer gas cell with caesium and nitrogen, achieving high sensitivity and bandwidth, and offering potential for scalable manufacturing.

Contribution

First implementation of an alignment-based magnetometer with a buffer gas cell, enabling scalable production and robust operation with high sensitivity.

Findings

Achieved 325 fT/√Hz sensitivity at 10 kHz

Operates at 55°C with a single laser beam

Potential for rapid commercialization due to microfabrication

Abstract

Alignment-based optically pumped magnetometers (OPMs) are capable of measuring oscillating magnetic fields with high sensitivity in the fT/sqrt(Hz) range. Until now, alignment-based magnetometers have only used paraffin-coated vapour cells to extend the spin relaxation lifetimes of the alkali vapour. The drawback of these cells is that they are hand-blown and are therefore time-intensive, and somewhat unreliable, to produce. Buffer gas cells, on the other hand, can be manufactured on a mass scale using microfabrication techniques. We present the first demonstration of an alignment-based magnetometer using a buffer gas vapour cell containing caesium (Cs) alkali vapour and nitrogen (N2) buffer gas. The OPM is operated at 55 degrees C and we achieve a 325 fT/sqrt(Hz) sensitivity to 10 kHz oscillating magnetic fields with an 800 Hz bandwidth. The alignment-based magnetometer uses a single laser beam for optical pumping and probing and could potentially allow for more rapid commercialisation of radio-frequency OPMs, due to the robustness of the one-beam geometry and the potential for mass-scale microfabrication of buffer gas cells.