Crosstalk reduction in optically pumped magnetometers arrays for biomagnetic measurement

Magnetoencephalography based on the compact OPM (Optically Pumped Magnetometer) array offers a series of advantages, such as low cost and wearability, and is gradually being used in brain science research and the diagnosis and treatment of brain diseases, such as epilepsy and dementia. As the distance between parametric resonance spin-exchange relaxation-free OPM sensors decreases, the array experiences increased crosstalk effect. We design a low-crosstalk coil to suppress magnetic field leakage, thereby reducing the impact of crosstalk. We compare the field leakage of the low-crosstalk coil and the Helmholtz-like coil and validate the performance of the coil using a 2 × 2 OPM array. The low-crosstalk coil demonstrates improved magnetic field suppression performance, and the noise floor of the OPM array reduces from ∼45 to 20 fT/Hz1/2.