The Influence Of Laser Source On The Signal Of Optical Magnetic Resonance

The laser optically pumped cesium magnetometer is a magnetic measurement instrument that is used to measure the absolute total intensity magnetic field, it is based on that the energy levels of cesium atoms in a magnetic field produces Zeeman effect and makes use of the principle that laser pumping and the RF magnetic field produce magneto-optical double resonance to make. Laser-pumped cesium atom is a core part of magnetometer structure.This article first introduces the cesium (Cs) atomic energy level structure and the basic nature and in the external magnetic field how to occur the coupling of I-J to form the hyperfine structure and Zeeman sublevels. It is given optical pumping magnetometer theoretical analysis and system design principles in this paper. Introduce the 894nm pump laser diode light source in the system structure; its performance parameter has crucial effect to optical pumping. Then under a simple three-level system, the detailed analysis the pumping mechanism of Zeeman sublevels of the cesium atom in the left-hand circularly polarized light beam. To obtain the stronger the probe light the magnetic resonance signals, we could make the Zeeman sublevels of cesium atoms higher the degree of polarization. The Innovation is to use the approximate the form of the optical Bloch equations by ML Harris, analysis and calculation population change of the cesium atom in ground state Fg=4, Fg=3 and the excited states Fe=4, by which we get the rate equation of the Zeeman sub-level population of cesium atoms and the time evolution function of Zeeman sub-level population of ground state and excited states. At last we analyze the impact of the laser light intensity, detuned frequency and polarization to the populations of the cesium atomic Zeeman sub-levels. Which can select the appropriate laser output parameters make the Fg=4 ground state to produce the greatest polarization. These parameters are very important for increasing partial polarizated degree of the cesium atomic level and improving optical-magnetic resonance signal.