光腔衰荡法是一种高反射率的测量技术.在腔长失调的情况下,根据高斯光束空间传输表达式和光腔衰荡法测量原理,建立了反射率测量的理论模型.利用模拟计算,得到了腔长失调对衰荡信号的影响.通过与实验现象相比较,证明了理论分析方法是合理的.

The cavity ring-down spectroscopy is a kind of measuring reflectivity technique. According to propagation equation of Gaussian beam and metrical principle of cavity ring-down, the theory model is set up for reflectivity measure with influence of length misadjustment Based on this model, it is numerically simulated that influence of length misacUustment of ring-down cavity on its output signal. The results show the excellent agreement between simulation and experiment, and prove that the theory model is accurate.