Peng Chuanqian, Gong Hengxiang, Gao Zhonghua, Wang Gang, Liang Xiao, He Yumei, Dong Xiaohao, Wang Jie
Appl Opt. 2021 Nov 10;60(32):10114-10119. doi: 10.1364/AO.438457.
In the present study, we proposed a new type of autocollimator for high-accuracy angular measurement within a large angle range. The new system comprises a traditional autocollimator and Risley prisms, and it employs the normal tracing method to measure the angle. By rotating the Risley prisms, the outgoing beam of the autocollimator can be deflected close to the normal direction of the reflecting mirror and then reflected back to the system by the mirror along the near normal direction to realize normal tracing. Based on the angle measured by the the autocollimator and the rotation angles of Risley prisms, we can calculate the tilt angle of the mirror. Since the beam returns to the system close to the original path, the angle error caused by aberration, optical component processing defects, nonuniform refractive index, and so on, can be ignored. Due to the normal tracing measurement method, theoretically, the angle error is not affected by the working distance. ZEMAX non-sequential simulation shows that the angle error caused by aberration in the new system can be significantly reduced.
在本研究中，我们提出了一种新型自准直仪，用于在大角度范围内进行高精度角度测量。新系统由传统自准直仪和里斯利棱镜组成，并采用法线跟踪方法来测量角度。通过旋转里斯利棱镜，自准直仪的出射光束可以偏转到接近反射镜的法线方向，然后由反射镜沿近法线方向反射回系统以实现法线跟踪。基于自准直仪测量的角度和里斯利棱镜的旋转角度，我们可以计算出反射镜的倾斜角度。由于光束几乎沿原路返回系统，因此由像差、光学元件加工缺陷、折射率不均匀等引起的角度误差可以忽略不计。由于采用了法线跟踪测量方法，理论上角度误差不受工作距离的影响。ZEMAX非序列模拟表明，新系统中由像差引起的角度误差可以显著降低。
