title: Magnetic field imaging with microfabricated optically-pumped magnetometers.
abstract: A multichannel imaging system is presented, consisting of 25 microfabricated optically-pumped magnetometers. The sensor probes have a footprint of less than 1 cm2and a sensitive volume of 1.5 mm × 1.5 mm × 1.5 mm and connect to a control unit through optical fibers of length 5 m. Operating at very low ambient magnetic fields, the sensor array has an average magnetic sensitivity of 24 fT/Hz1/2, with a standard deviation of 5 fT/Hz1/2when the noise of each sensor is averaged between 10 and 50 Hz. Operating 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 on average 76 ± 7 mW of power each. The heating power is provided by an array of eight diode lasers. Magnetic field imaging of small probe coils was obtained with the sensor array and fits to the expected field pattern agree well with the measured data.
authors.forename: Orang
authors.initials: O
authors.lastname: Alem
authors.forename: Rahul
authors.initials: R
authors.lastname: Mhaskar
authors.forename: Ricardo
authors.initials: R
authors.lastname: Jiménez-Martínez
authors.forename: Dong
authors.initials: D
authors.lastname: Sheng
authors.forename: John
authors.initials: J
authors.lastname: LeBlanc
authors.forename: Lutz
authors.initials: L
authors.lastname: Trahms
authors.forename: Tilmann
authors.initials: T
authors.lastname: Sander
authors.forename: John
authors.initials: J
authors.lastname: Kitching
authors.forename: Svenja
authors.initials: S
authors.lastname: Knappe