Influence of laser heating temperature characteristics on SERF atomic magnetometer

The SERF atomic magnetometer typically operates in a high-temperature and zero-magnetic-field regime. Among common heating methods, laser heating is a promising method since it is magnetically clean and stable. In this work, we for the first time introduce an orthogonal laser heating configuration to improve the temperature uniformity of the atomic cell, thereby enhancing the sensitivity of the atomic magnetometer. What's more, a theoretical model is provided to illustrate the relationship between temperature variation and sensitivity. The temperature distributions of different laser heating configurations are evaluated by the finite element method. Experimental measurements were conducted with a single-beam atomic magnetometer. The spatial distribution of the conversion coefficient within the atomic cell was constructed through a simulation method. And the results show that, compared with the coaxial heating configuration, the orthogonal heating configuration improves the magnetic field sensitivity by 11.3%. Experimental results show that the magnetic field sensitivity under coaxial heating configuration is 56fT/Hz, while that under orthogonal heating configuration is 48fT/Hz, representing a 14.3% improvement. Both the simulation and experiments demonstrate that the orthogonal heating configuration significantly enhances the temperature uniformity within the atomic cell, thereby improving the magnetic field sensitivity of the atomic magnetometer.