Development of 100 kHz optical pumped atomic magnetometer module for non‐magnetic shield

In recent years, various sensors for biomagnetic measurement have been researched and developed. These are mainly for low frequency small signals such as magnetocardiography. Optical pumped atomic magnetometer (OPAM) would rather be applicable to this high frequency signal since there is a valid signal at higher frequencies. However, the highly sensitive OPAM uses a magnetic shield and an anti‐vibration table, which makes the OPAM system larger. By packing the optical system in one case, you can develop an OPAM module that can measure even while moving. As a result, by using a phase‐locked loop, we have achieved a sensitivity of 2.548 pT/Hz1/2 for a 100 kHz magnetic signal in the presence of a bias magnetic field and electromagnetic noise.