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Differential Atomic Magnetometry Based on a Diverging Laser Beam



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


We 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, which serves to both optically pump the atoms and measure the transverse polarization. Operating the magnetometer in differential mode cancels common-mode noise and improves the sensitivity by a factor of 26 over single-channel operation. We also suggest ways in which the current sensitivity of 28\,pT/$\surd$Hz may be improved further without sacrificing size or simplicity.
Physical Review Letters


alkali atoms, atomic magnetometer, chip scale devices, differential detection, diverging beam, microelectromechanical systems (MEMS), optical pumping


Hodby, E. , Donley, E. and Kitching, J. (2007), Differential Atomic Magnetometry Based on a Diverging Laser Beam, Physical Review Letters, [online], (Accessed June 22, 2024)


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Created July 3, 2007, Updated February 17, 2017