为了能够较为准确地获得光反馈自混合干涉测量系统的反馈水平, 采用仿真分析光反馈自混合干涉信号和求解Lang-Kobayashi方程的方法, 得出反馈水平越高, 光反馈自混合干涉信号上干涉条纹的谷值与下干涉条纹峰值之差越大, 当反馈水平因子大于7.8时, 一些干涉条纹将消失; 同时由滞回现象可以推导出反馈水平因子的测量公式, 建立了测量模型, 并进行了仿真和实验验证。结果表明, 光反馈自混合信号干涉条纹幅度受反馈水平影响; 利用提出的测量模型可以判断光反馈自混合干涉实验信号的反馈水平机制, 当光反馈水平因子介于1和7.8之间时可以测出具体的光反馈水平因子值。

In order to obtain feedback strength of optical feedback self-mixing interferometry(OFSMI) systems exactly, OFSMI signals were simulated and analyzed and Lang-Kobayashi equations were solved. It is found that separation between the minimum of the up-side interferometric fringes and the maximum of down-side interferometric fringes grows as the optical feedback strength factor increases. Some interferometric fringes disappear when the factor is greater than 7.8. Besides, a formula about feedback strength factor was deduced from hysteresis phenomenon and a measurement model was set up. The simulation and experimental results show that OFSMI signal fringes are related to the optical feedback strength factor. The proposed model based on the formula about the factor can be used to judge regimes of OFSMI measurement systems and the value of optical feedback strength factor can be figured out when it is between 1 and 7.8.