Signal-processing electronics for stable and sensitive weak-field atomic vector magnetometers.

The article focuses on the development of compact, low-cost, and high-precision signal-processing electronics for a sensitive and stable three-axis atomic vector magnetometer designed for low-field detection. It addresses the challenge of interference caused by multiple modulation fields by implementing a frequency-selection scheme that aligns modulation frequency separations with the zero-response points of cascaded-integrator-comb (CIC) low-pass filters, effectively suppressing beating signals that degrade long-term sensor stability. The electronics utilize a field programmable gate array (FPGA) to generate modulation signals, perform lock-in amplification, and execute closed-loop feedback control, achieving a field sensitivity better than 40 fT/Hz^1/2 at 1 Hz and measurement stability below 1.5 pT over 10,000 seconds. The work also outlines plans to integrate laser diode temperature and current control electronics to further miniaturize the magnetometer system.