High-sensitivity Magnetic Microscope using an Optically Pumped Magnetometer and Flux Guides*

Various applications in neuroscience research require high-sensitivity magnetic microscope. To meet this demand, we recently proposed an original approach of combining a cm-size optically pumped magnetometer (OPM) with flux guides (FGs) in order to develop a compact, portable, high-sensitivity OPM-FG magnetic microscope. The OPM based on lasers and alkali-metal vapor cells is the most sensitive cryogen-free magnetic sensor, approaching femtotesla sensitivity with cm-scale resolution. The FG serves to transmit the magnetic flux from a microscopic source of magnetic field to the cm-size OPM to simultaneously improve the resolution and sensitivity. In this talk, we will describe our approach and present numerical tests of sensitivity and resolution. Our numerical tests show that an optimized OPM-FG has sufficient resolution and sensitivity for the detection of a small number of neurons, which would be an important milestone in neuroscience.