Preliminary Investigation On CPT Atom Magnetometer

With the development of the economy and technology, the measurement of physical constant is more and more important. The magnetic field is widespread in the space, the measurement of magnetic field is applied in many field, such as geophysical surveying, industrial detection, medical diagnoses, and national defense etc. This thesis refers to the investigation of the magnetometer which can be used out of lab.To obtain high sensitivity and accuracy, the atom magnetometer based on quantum effects is a good candidate. One type of magnetometer investigated in the thesis is the optical pumping magnetometer with high sensitivity and accuracy. The other type is the CPT magnetometer based on coherent population trapping. After finishing the initial principle experiment, we evaluate the noise of the signal with the magnetic field steps. We investigate the way to improve the signal-to-noise ratio (SNR), at the same time we find the reason why the signal distortion when the magnetic field is a little higher. At last, the whole system can work in a closed-loop.In the chapter1, the background of the investigation of the magnetometer, the principle of some magnetometers and their advantages and disadvantage are introduced. In the chapter2, the principle of optical pumping and CPT magnetometer is discussed. The construction of the experiment system, the processing and analysis of the signal are presented.In the chapter3, the main modules of the system are introduced.In the final chapter, a brief summary and promising prospect of the development and application of the magnetometer are given.