基于自洽方程组及传递函数的腔衰荡信号研究

Analysis of the cavity ring-down signal based on self-consistent equations and the transfer function

为了更好地理解腔衰荡技术的物理本质和测量过程从而更好地分析腔衰荡信号,利用自洽方程组、结合光学无源腔的品质因子Q值定义对腔衰荡技术的基本原理进行了推导,并结合该方程组有关系数的物理意义,引入传递函数的概念分析了不同情况下的腔衰荡信号的基本特征。结果表明,这种分析方式可靠,可为腔衰荡技术在超低损耗薄膜性能标定及腔内介质的吸收光谱测量等领域的应用提供理论指导。

In order to better understand the physical nature and measurement process of the cavity ring-down technique and analyze the signal, the self-consistent equations and the Q concept of a passive optical cavity were used to deduce the basic principle. The transfer function was introduced to analyze the essential features of different signals under different conditions. Results show that this analytical method is reliable and can provide theoretical guide for cavity ring-down measurements in different areas such as the calibration of ultra-low loss films and the measurement of the intra-cavity absorption spectrum.