Optically pumped magnetometers for MEG

Abstract

Optically pumped magnetometers (OPMs) have seen rapid progress over the last decade in terms of performance and technology development. As highly sensitive room-temperature magnetometers, they present several advantages over superconducting quantum interference device (SQUID) sensors, such as the possibility for on-scalp magnetoencephalography (MEG) with conformal geometries and low-maintenance systems. We review the state of the art and different types of low-field OPMs, as well as recent MEG demonstrations with OPMs. Several challenges remain, such as the demonstration of large OPM multichannel systems, their limited dynamic range and bandwidth, and proper knowledge of sensor locations to name just a few. Certainly, OPMs present a promising technology to complement existing SQUID-based installations.