Functional Micro-neuroimaging with an Optically Pumped Magnetometer and Flux Guides

A key challenge in neuroscience is understanding human brain function and behavior at different scales, critical for many applications. One powerful modality of imaging neuronal activity is magnetoencephalography (MEG) that sensitively measures the magnetic fields produced by neuronal electrical activity. But today, MEG typically measures only cm-scale neuronal activity due to the trade-off between sensitivity and resolution in state-of-the-art magnetic sensors. Thus, many important problems requiring microscopic resolution remain unsolved. We recently proposed to develop a magnetic microscope to improve the resolution and the sensitivity. This development was realized by a novel approach of combining a cm-size optically pumped magnetometer (OPM) with high-permeability flux guides (FGs). The OPM is the most sensitive cryogen-free magnetic sensor based on lasers and atomic vapor cells. The FG serves to transmit the magnetic flux from a microscopic magnetic source to the OPM. In this talk, we will explain the approach of our high-sensitivity magnetic microscope and present our recent progress.