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

We present the electronics developed for a sensitive and stable atomic vector magnetometer used in low-field detections. These electronics are required to be not only highly reliable and sophisticated for signal processing but also compact in size and low cost in resource consumption for the purpose of miniaturization. In addition, this magnetometer works with multiple modulations, where the interferences between harmonics of modulation fields often disturb the long-term measurements of the sensor. We work out a robust method to eliminate this problem by choosing the modulation frequencies with separations to match the minimum response points of the low-pass filters used in the demodulation processes. We validate the performance of the electronics and the frequency-selection scheme of the modulation fields with corresponding experimental results.