The Measuring Method of Atomic Polarization of Alkali Metal Vapor Based on Optical Rotation and the Analysis of the Influence Factors
SHANG Hui-ning, QUAN Wei*, CHEN Yao, LI Yang, LI Hong
Science and Technology on Inertial Laboratory, Fundamental Science on Novel Instrument & Navigation System Technology Laboratory, Beijing University of Aeronautics and Astronautics, Beijing 100191, China
Abstract：High sensitivity measurements of inertia and magnetic field could be achieved by utilizing a category of devices, which manipulate the atomic spins in the spin-exchange-relaxation-free regime. The alkali cell which contains the alkali metal vapor is used to sense magnetic field and inertia. The atomic number density of alkali vapor and the polarization of alkali metal vapor are two of the most important parameters of the cell. They play an important role in the research on atomic spins in the spin-exchange-relaxation-free regime. Besides, optical polarization plays an important role in quantum computing and atomic physics. We propose a measurement of alkali vapor polarization and alkali number density by detecting the optical rotation in one system. This method simplifies existing experimental equipment and processes. A constant bias magnetic field is applied and the Faraday rotation angle is detected by a bunch of the probe beam to deduce alkali-metal density. Then the magnetic field is closed and a bunch of the pump laser is utilized to polarize alkali-metal. Again, the probe beam is utilized to obtain the polarization of alkali metal. The alkali density obtained at first is used to deduce the polarization. This paper applies a numerical method to analyze the Faraday rotation and the polarization rotation. According to the numerical method, the optimal wavelength for the experiment is given. Finally, the fluctuation of magnetic field and wavelength on signal analysis are analyzed.
Key words：Atomic number density;Atomic polarization;Optical polarization rotation
尚慧宁，全 伟*，陈 瑶，李 洋，李 红 . 基于光偏振旋转效应的碱金属气室原子极化率测量方法及影响因素分析 [J]. 光谱学与光谱分析, 2016, 36(02): 305-309.
SHANG Hui-ning, QUAN Wei*, CHEN Yao, LI Yang, LI Hong . The Measuring Method of Atomic Polarization of Alkali Metal Vapor Based on Optical Rotation and the Analysis of the Influence Factors . SPECTROSCOPY AND SPECTRAL ANALYSIS, 2016, 36(02): 305-309.
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