从三镜法布里-珀罗(F-P)腔出发,建立了非准直外腔三重回馈自混合干涉的理论模型,并进行了数值模拟和实验验证。分析了3种情况下影响自混合干涉光强调谐特性的因素:1)准直外腔二,三重回馈;2)非准直外腔二,三重回馈;3)外腔加入λ/4波片时的回馈。实验结果与理论分析相吻合。研究表明,该自混合干涉系统的分辨率达到λ/6;自混合干涉输出信号与腔反射镜的反射率、外腔的准直性以及腔内置入镜片有关;外腔中加入λ/4波片时的自混合干涉信号与非准直外腔自混合干涉信号类似;二,三重回馈自混合干涉信号携带了反射体位移方向信息,因而更易实现位移方向判断。

Based on the Fabry-Perot (F-P) cavity model with three mirrors,the theoretical model of the triple feedback effect of non-alignment cavity was established,numerically simulated and experimentally validated. The factors affecting the power turning properties of the self-mixing interference were analyzed under three conditions:1) double and triple feedback effect of alignment cavity;2) double and triple feedback effect of non-alignment cavity;3) the feedback effects when a λ/4 plate was inserted into the external cavity. The experimental results are in good agreement with theoretical analysis. It is shown that,the resolution of the self-mixing interference system can be up to λ/6;the self-mixing interference signal is related with the reflectance of the cavity mirror,the alignment of the cavity mirror and other plates in the external cavity;the self-mixing interference signal in condition (3) is similar to that of the non-alignment cavity;the information of the displacement direction of the reflector is contained in the self-mixing interference signal of double and triple feedback,so it could be easily distinguished.