Digital servo system based on FPGA for optically pumped magnetometer

This paper describes the design and implementation of a digital servo system based on FPGA for one optically pumped magnetometer. The digital servo system based on FPGA incorporates an analog to digital converter, a digital to analog converter and a direct digital synthesizer. In a simple test setup, the Zeeman transition frequency is detected and locked by this digital servo system. The measurement of the magnetic field is experimentally realized. This digital servo system is designed to detect and lock the Zeeman transition frequency in mind but should be adaptable to a variety of other similar system. With a minor change, this digital servo system is already applied in our atomic clock.