热透镜技术的单柱面聚焦透镜差分测量构型

Differential measurement configuration with single cylindrical focusing lens for thermal lens technique

提出了一种基于单柱面聚焦透镜的热透镜技术差分测量构型,并采用相移理论和高斯光束ABCD传输定律建立了热透镜信号理论模型,导出了最优构型条件及测量灵敏度理论极限,结果表明该测量构型能够获得与双柱面聚焦透镜测量构型相同的测量灵敏度。采用理论计算及有限元分析相结合的方法分析了构型参数对探测平面光强分布及热透镜信号幅值的影响,理论结果和有限元结果的一致性证明了单柱面聚焦透镜差分测量构型的可行性及理论模型的正确性。

A differential measurement configuration with single cylindrical focusing lens for thermal lens technique is proposed and a theoretical model based on the optical phase shift theory and the ABCD rule for Gaussian beam propagation is developed to describe the thermal lens amplitude.The optimal configuration condition and the theoretical limit of measurement sensitivity are derived.The theoretical results show that this measurement configuration can obtain the same measurement sensitivity as the measurement configuration with double cylindrical focusing lens.The influences of configuration parameters on the light intensity distribution on the detection plane and the thermal lens amplitude are analyzed by the theoretical model,as well as by the finite element method.The both reach a good agreement,which proves the validity of differential measurement configuration with single cylindrical focusing lens and the correctness of the theoretical model.