Rapid Electromagnetic Induction Imaging With an Optically Raster-Scanned Atomic Magnetometer

We present an apparatus to overcome the limitations of mechanical raster scanning in electromagnetic induction imaging (EMI) techniques by instead performing a 2-D optical raster scan within the vapor cell of a radio frequency atomic magnetometer (RF-AM). A large cuboidal 87Rb vapor cell is employed to act as the medium of an RF-AM with the pump and probe beams translated in the cell via acousto-optics. The technique is shown to give robust and repeatable magnetic measurements over the cell volume and successfully resolves conductive targets with EMI. Optical raster scanning removes the limitation of slow mechanical actuation, and a fast imaging procedure is enacted resolving conductive targets at a rate of 40 ms/pixel.