基于铯原子线性法拉第磁光效应的应用

Application of the linear Faraday's magnetic-optic effect based on cesium atom

分析了铯(Cs)原子作为旋光介质的线性法拉第磁光效应。采用二能级模型解释了铯原子与光的相互作用,并利用琼斯矩阵推导了当激光器的频率处于铯原子共振线时,经过铯气室的线偏振光的旋转角与外加磁场的关系式,利用此关系式可测量磁场强度的大小和气室内铯原子的浓度。实验采用852nm分布反馈半导体激光器作为光源,依次通过起偏器、铯气室和偏振光束分裂器,测量了法拉第旋转角与磁场的关系曲线以及铯原子浓度,测量值与理论值基本相符。

Linear Faraday＇s magnetic-optic effect which uses the cesium atom as the medium is analyzed.The two-level atom model is used to explain the interaction between the cesium atoms and light.When the laser frequency is equal to the cesium atomic resonance line,the relation between the rotated angle of the incident linear polarized light and the magnetic field is derived from Jones matrix.According to the equation,the magnetic field and the density of cesium vapor can be measured.The optical measure system is composed of 852nm semiconductor distributed feedback laser,polarizer,cesium vapor cell and polarized beam splitter.The experimental result and theoretical value are in good agreement.