基于抽运-探测法的皮秒反斯托克斯拉曼频移器的理论研究  

Theoretical study of picosecond anti-Stokes Raman frequency converter based on pump-probe method

作　　者：王聪 吕冬翔 Wang Cong;LüDong-Xiang(School of Science,Tianjin University of Technology,Tianjin 300384,China;The 18th Research Institute of China Electronics Technology Group Corporation,Tianjin 300384,China)

机构地区：[1]天津理工大学理学院,天津300384 [2]中国电子科技集团公司第十八研究所,天津300384

出　　处：《物理学报》2021年第9期272-281,共10页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:11504268);天津市教委科研计划(批准号:2014KJ240)资助的课题。

摘　　要：采用拉曼频移器在晶体介质中利用相干反斯托克斯散射效应可以获得超短脉冲(皮秒)反斯托克斯激光.基于抽运-探测法的晶体拉曼频移器可以实现相干反斯托克斯散射的共线相互作用,从而可以有效提高反斯托克斯光的转化效率.本文在平面波近似下建立了基于抽运-探测法的皮秒反斯托克斯拉曼频移器的耦合波方程组,引入归一化参量对方程组进行了归一化处理.通过数值计算,得到了描述皮秒反斯托克斯拉曼频移器运行的一组普适理论曲线,分析了归一化拉曼增益系数G、归一化相位失配参数△K以及探测光脉冲能量占基频光总能量的比值r_(probe)三个变量对反斯托克斯拉曼频移器性能的影响,确定了实现高效反斯托克斯转化时各归一化变量的合理取值.采用实验数据对该理论模型的正确性进行了验证,反斯托克斯转化效率的理论值与文献数据基本一致.Ultra-short pulse(picosecond) anti-Stokes laser can be obtained by using Raman frequency converter in a crystal medium by the coherent anti-Stokes Raman scattering effect. The crystalline Raman frequency converter based on the pump-probe method can realize the collinear interaction of coherent anti-Stokes Raman scattering,thus effectively improving the conversion efficiency of the anti-Stokes light. Theoretical simulation is an important means to study laser operation. Coupled wave equation is widely used to study the characteristics of Raman laser and anti-Stokes laser. Although the coupling wave theory of anti-Stokes Raman frequency shifter reported previously can reflect the operation law of the frequency shifter, the optimization of the frequency shifter and the influence of the frequency shifter parameters on the output characteristics of anti-Stokes laser have not been reported so far. In this paper, the picosecond anti-Stokes Raman frequency converter based on the pump-probe method is studied theoretically. Considering the generation of the first Stokes light in the probe channel and the second Stokes light in the pump channel, the coupled wave equation of the collinear picosecond anti-Stokes Raman frequency converter is established under the plane wave approximation. Without loss of generality, four dimensionless comprehensive parameters are introduced to normalize the equations. A set of universal theoretical curves describing the operation of the Raman frequency converter is obtained. The numerical solutions of the equations show that the performance of the Raman frequency converter mainly depends on three parameters: the normalized phase mismatch parameter △K, the normalized Raman gain coefficient G, and the energy ratio of the probe light to the fundamental light rprobe. The reasonable values of normalized variables are determined when the high efficiency anti-Stokes conversion is realized. Experimental data are used to verify the correctness of the theoretical model. The theoretical value of the an

关 键 词：相干反斯托克斯散射 共线四波混频 耦合波方程 归一化理论 

分 类 号：TN248[电子电信—物理电子学]