Research Of Highly Sensitive Rubidium Atomic Magnetometer

From the Sinan that can only indicate the direction of the magnetic field in the Warring States period,to the most sensitive superconducting quantum interferometer device?SQUID?,the pace of developing ultra-high sensitivity magnetometers has never stopped.The ultra-sensitive atomic magnetometer is an instrument for measuring the weak magnetic field by the Larmor precession of the alkali metal atomic vapor in the magnetic field after the optical pump.This magnetometer is comparable to superconducting quantum interferometers device in sensitivity,but does not require ultra-low temperature liquids to maintain the superconducting state of the instrument.Therefore,the alkali metal atomic magnetometer is ultra-highly sensitive,low cost,and compactable.This thesis systematically designs and optimizes the pump-probe configuration of the Rb atomic magnetometer,achieving a sensitivity of better than 20 fT/Hz^1/2.The results of this paper are as follows?1?The active and passive magnetic shielding system is designed.Passive magnetic shielding is a high shielding coefficient magnetic shield made of permalloy with high magnetic permeability.Theoretically,the magnetic shielding coefficient is 10⁸,the actual internal residual magnetic field is less than 1 nT.The active magnetic shielding is a high uniformity shim coil.The axial unevenness is less than one thousandth.?2?Design and processing the optical path system of the pump-probe configuration and the frequency-locked system based on the saturated absorption spectrum of the alkali metal atom.?3?Design and processing the heating oven and the internal support of the magnetic shield.The square Rb atomic vapor cell is conveniently placed in the center of the heating oven.The twisted heating wire is wound around the surface of the heating oven.Non-magnetic heating and temperature control are realized by means of high-frequency alternating current heating and PID feedback,and the temperature control accuracy is0.1?.?4?Optimize the laser parameters,improve the response amplitude and signal-to-noise ratio of the magnetic field signal,and optimize the sensitivity of the magnetometer.