Research On Atomic Filtering Technology Based On Stimulated Raman Scattering

With the increasing maturity of the interaction technology between light and matter,the issue of space optical communication has always been widely concerned by researchers at home and abroad.In order to detect weak signal light in strong continuous background noise,the research of atomic optical filter in free space quantum key distribution and laser communication has attracted more and more attention.This paper proposes a filter technology based on stimulated Raman scattering,establishes a theoretical model of rubidium atoms and cesium atoms,and analyzes the effects of various parameters on the transmission coefficient and gain coefficient of the atomic filter through numerical simulation.The main content of the paper is as follows:1.The research background and significance of atomic optical filters and stimulated Raman scattering-based atomic filters are analyzed and introduced,the principle and research situation are summarized,including atomic resonance filter,Faraday anomalous dispersion atomic filter,Voigt filter and laser-induced circular dichroic atomic filter.Briefly introduce the main content and structure arrangement of the paper.2.Briefly describe the classification of Raman scattering,including spontaneous Raman scattering and stimulated Raman scattering,outline the principle and theoretical basis of Raman scattering,and use Schrodinger equation to describe atom quantized system,and Maxwell equation to describe the theoretical system of classical light field,introduces the filtering mechanism of Faraday anomalous dispersion atomic filter.3.Based on the principle of stimulated Raman scattering and atomic filter,this paper proposes a theoretical model of stimulated Raman scattering atomic filter with cesium atom transition in the ground state,and uses numerical simulation to analyze different working parameters.The influence of the detuning amount of the pump light,the temperature of the atomic vapor cell and the length of the atomic vapor cell on the transmission coefficient,and the influence of the change of the coupling optical power on the gain coefficient.4.Propose the theoretical model of the atomic filter for stimulated Raman scattering of the rubidium atomic transition in the excited state,derive the expression of gain coefficient and transmittance,and use numerical simulation to analyze the Raman pumping rate and the atomic vapor cell's temperature,the length of the atomic vapor cell for filtering and the length of the atomic vapor cell for gaining affect the transmission characteristics of the atomic filter.The research on atomic optical filters,especially the use of stimulated Raman scattering atomic filters for weak detection light amplification,is of great significance.In this paper,the Faraday anomalous dispersion atomic filter for stimulated Raman scattering in the ground state and in the excited state is analyzed and studied in detail by numerical simulation methods.The research results provide a reasonable reference basis for applications such as radar,solar highresolution imaging,space optical communications,underwater communications,and laser frequency stabilization.