Research On All-fiber Weak Magnetic Sensing

In recent years,with the widely application of weak magnetic field detection and measurement technology in military,medical,nuclear magnetic resonance,space exploration and other fields,people have put forward higher requirements for the performance of magnetic field sensors and magnetic field detection sensitivity.The atomic magnetometer developed in this century is a new-generation magnetometer with the highest sensitivity and volume up to the chip level to meet people's increasing demands.It has important research value to simplify the structure of the polarization measurement light and rotation angle in the weak magnetic measurement structure of atomic magnetometer and simplify its structure.In this paper,combined with the high-sensitivity weak magnetic field measurement thought 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:Firstly,introducing the background and significance of the research.The working principle and development history of several typical magnetometers for measuring weak magnetic fields are summarized,and the research status and development trend of atomic magnetometers at domestic and abroad are introduced.Secondly,Based on the description of the working principle of the atomic magnetometer for measuring the weak magnetic field,the theoretical basis of the phase difference detection of the optical interference signal is analyzed,the output form of the optical interference signal is described,the method of modulation and demodulation of the interference signal and the signal detection method are mainly analyzed,etc..Next,The use of circularly polarized light to detect the optical rotation angle of the atomic magnetometer was introduced.The 45° welding in the light path was tested.The simulation and experiment of the magnetic field generating device and the magnetic shielding device were completed,and the output of the system was simulated.The production of atomic chambers in the system was introduced.Finally,Design an all-fiber atomic weak magnetic sensing detection system,outline the principle of overall signal detection,complete system debugging and experiments,and analyze the results.