Research On Meachanism And Structure Of All-fiber Weak Magnetic Field Sensing

In recent years,with the widely use of weak magnetic field detection and measurement technology in military,medical,nuclear magnetic resonance,space exploration and so on,people set higher requirements for the magnetic field sensor performance and magnetic field detection sensitivity.Developing in this century,the atomic magnetometer,which has the highest sensitivity,and chip-level volume,meets the increasingly needs of people.The accurate measurement of the optical rotation angle in the atomic magnetometer is a important step to improve the sensitivity of the magnetic field measurement,and it has important research value.In this paper,combined with the high-sensitivity weak magnetic field measurement technique of atomic magnetometer structure and the high precision measurement advantage of optical fiber sensing technology,an all-fiber weak magnetic sensor structure is proposed and studied deeply.The major study context in this paper includes:The first chapter is introduction,which is mainly talked about the background and significance of the research,and several typical magnetometers of the weak magnetic field.The research status and development trend of the atomic force magnetometer in the weak magnetic field are introduced in detail,and the content of this paper is also discussed.Secondly,the working principle of measuring the weak magnetic field by using the atomic magnetometer structure is analyzed.According to the characteristics of alkali metal atoms,the process of polarized spin magnetic moment around the magnetic field of Ramon precession,pumped polarized atoms and detection photo detection is analyzed.Through the theoretical analysis and simulation calculation,frequency response curves of light angle of Cs atomic magnetometer in different polarized light detection are obtained.Thirdly,an all-fiber weak magnetic field measurement scheme is proposed.This paper briefly analyzes the basic working principle of using the circularly polarized light to detect the weak magnetic field measurement of the atomic spin precession in the all-fiber weak magnetic sensing structure.Finally,the experimental system platform is designed,and the devices selected in theexperiment are briefly introduced.The performance of each device is tested.Finally,the experimental device of the optical path sensing part is built and the experimental results are analyzed.