Magnetic field imaging with microfabricated optically-pumped magnetometers

Published

March 28, 2017

Author(s)

Orang Alem, Rahul Mhaskar, Ricardo Jimenez-Martinez, Dong Sheng, John LeBlanc, Lutz Trahms, Tilman Sander, Svenja A. Knappe

Abstract

A multichannel imaging system is presented, consisting of 25 microfabricated optically-pumped magnetometers. The sensor probes have a footprint of less than 1 cm2 and a sensitive volume of (1.5 mm)3. They are connected to a control unit through optical fibers of length 5 m. At very low ambient magnetic fields, the magnetic sensors array has an average sensitivity of 24 fT/Hz1/2, with a standard deviation of 5 fT/Hz1/2 when the noise of each sensor is averaged between 10 and 50 Hz. In Earth's magnetic field, the magnetometers have a field sensitivity around 5 pT/Hz1/2. The vacuum-packaged sensor heads are optically heated and consume 76 ± 7 mW of power each. The heating power is provided by an array of 8 diode lasers. As an example, magnetic field images of small probe coils were obtained with the sensor array. Fits to the expected field pattern agree well with the measured data.

Citation

Optics Express

Pub Type

Journals

Keywords

Laser sensors, Optical instruments, Micro-optical devices, Spectroscopy, atomic

Citation

Alem, O. , Mhaskar, R. , Jimenez-Martinez, R. , Sheng, D. , LeBlanc, J. , Trahms, L. , Sander, T. and Knappe, S. (2017), Magnetic field imaging with microfabricated optically-pumped magnetometers, Optics Express (Accessed October 18, 2025)