Applied Physics Letters

Differential atomic magnetometry based on a diverging laser beam

E. Hodby, Elizabeth A. Donley, John E. Kitching

Published Jul 2, 2007• 16 citations

Abstract

The authors demonstrate a novel atomic magnetometer that uses differential detection of the spatially diverging components of a light field to monitor the Larmor precession frequency of atoms in a thermal vapor. The design is implemented in compact form with a micromachined alkali vapor cell and a naturally divergent light field emitted by a vertical-cavity surface-emitting laser. Operating the magnetometer in differential mode cancels common-mode noise and improves the sensitivity by a factor of 26 over single-channel operation. They also suggest ways in which the current sensitivity of 28pT∕√Hz may be improved further without sacrificing size or simplicity.

DOI: 10.1063/1.2753763

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