Crosstalk analysis and suppression of optically pumped magnetometer array for bio-magnetic field measurement systems

Crosstalk between neighboring optically pumped magnetometers (OPMs) limits the localization accuracy of the magnetoencephalography systems based on high-density OPMs. In this study, we develop a comprehensive model to describe the relationship between the optimal modulation-field amplitude of OPMs and their operating parameters. Our model reveals that sensors have distinct optimal modulation amplitudes under different operating parameters. Meanwhile, by appropriately reducing the vapor temperature or increasing the pump intensity, the susceptibility of OPM response to change in the modulation amplitude can be significantly reduced and thus decreasing the influence of the crosstalk. Furthermore, considering the layout of our high-resolution OPM array, the calculation equation for the coil magnetic field is improved for achieving the optimal modulation amplitude for each sensor. Consequently, we successfully suppress the crosstalk associated with the modulation-field amplitude. Our approach facilitates the rapid and accurate suppression of the crosstalk between channels, paving the way for OPM array applications.