对反射旋转体引起聚焦激光自混合干涉信号位相与旋转角度的非线性关系进行了研究, 提出了一个实验参数的优化方法来降低该非线性效应引起的非线性角度测量误差。重新评估了自混合干涉角度测量在测量范围扩大后的物理近似条件, 从理论上分析了实验参数给角度测量带来的误差影响并进行了模拟仿真, 提出了利用该非线性关系判别反射体旋转方向的方法。最后, 进行了激光自混合干涉角度测量实验并给出若干个实验参数条件下分别得到的角度测量结果。实验结果表明, 实验参数优化后, 角度测量误差大幅减少; 在最优情况下, 比未优化方法的测量精度提升了一个数量级, 可达10-5 rad, 证明了提出的实验参数优化方法和反射体旋转方向判别方法的有效性。实验结果还显示, 使用提出的方法在提高测量范围的同时仍能进行高精度的角度测量, 从而进一步拓宽了基于反射体旋转引起的激光自混合干涉效应的应用范围。

The nonlinear relationship between phase and rotation angle of a self-mixing interference signal caused by a reflector rotation was researched and an experimental parameter optimization method was proposed to reduce the nonlinear angle measurement errors from the nonlinear effect above mentioned. The physical approximate conditions in self-mixing type interferometry were re-evaluated for enlarged angle measurement range, the effect of experimental parameters on the errors of angle measurement was analyzed theoretically and simulations were carried out subsequently. A new method relied on the nonlinear relationship to recognize the direction of rotation was introduced. Finally, self-mixing interference experiments for angle measurement were performed and the results corresponding to different conditions were given. The results show that errors of focused laser self-mixing type interferometry are reduced remarkably, and the measurement precision reaches to 10-5 rad, which is increased by one order of magnitude as compared with that of the non-optimized scheme. These results verify the evidences of the optimization scheme for the recognition of rotating direction and the improvement of measurement accuracy. Moreover, as the high accuracy of measurement maintains angle measurement ranges enlarged, it broadens applications of laser self-mixing interferometry based on the reflector rotation.