Parameters optimization of optical pumped Mz/Mx magnetometer based on rf-discharge lamp

Abstract Optical pumped magnetometer (OPM) aiming at the measurement of Earth’s magnetic field, is firstly optimized by optical simulation, as to maximize the efficient pumping light. Then Mz-magnetometer and Mx-magnetometer are respectively realized in this work, and the correspondent signals are analyzed. The temperature of rf-discharge lamp, the temperature of vapor cell and the amplitude of radio frequency field (RF) are optimized. In Mz mode, the FWHM/SNR of the absorption curve of magnetic resonance (Mz signal) gives 1.3 Hz under 10, 000 nT, with a correspondent field resolution 29.6 pT. Additionally, the scanning rate of RF should be set to be lower than 40 kHz/s, as to obtain a well Lorentzian form of Mz signal. In Mx mode, the free induction decay (FID) signal and Rabi signal are obtained and analyzed. By sweeping the frequency of RF, a so-called “peak splitting” of Mx signal is found to be in existence at the magnetic resonance point theoretically and experimentally, and thereby a suitable amplitude of RF needs to be carefully determined for achieving a satisfied amplitude of Mx signal, as well as for a better sensitivity of magnetometer.