Digital-locking optically pumped cesium magnetometer

Abstract

Lamp-based optically pumped Cesium magnetometer is one kind of commercial quantum magnetometers. In whatever military or civil magnetic field measurement, the practical optically pump magnetometer possesses a very important application value as well as prospect. This paper presents a portable lamp-pumped and digital-locking cesium atomic magnetometer, including the probe for detecting Zeeman transition signal and the digital servo system for locking the Zeeman transition frequency based on NI PCI-4461. The probe is lamp-based and as compact as 17 cm × 6 cm × 6 cm in size. The design of the servo system is to use frequency switching (at two frequencies) to create two corresponding voltages from the probe. When the voltages are equal, the center of the two frequencies appears to be the Zeeman transition frequency. The measurement of the magnetic field is experimentally realized with the noise level of 22 pT. The magnetometer is portable and highly compact with good sensitivity and has the potential of practical usage in the future.