为了抑制环境振动引入的测量误差,实现对球面光学元件面形的动态检测,提出了一种基于微偏振片阵列的反射式针孔点衍射干涉系统。该干涉系统使用短相干激光光源获得两束相干光,通过调节两束偏振光的光强比调节干涉条纹的对比度,利用集成微偏振片阵列CCD相机采集的单帧图像获得4幅相移干涉图,实现动态检测。用该干涉系统和ZYGO干涉仪测量同一凹面镜样品,得到的面形结果相吻合,验证了该干涉系统测量结果的准确性。在实验测量平台上外加电动机产生振动条件,结果表明,当振动速度小于16 μm/s时,都可得到较准确的面形测量结果,表明该干涉系统的抗振性能较好。

In order to suppress the measurement error caused by environmental vibration and realize the dynamic detection of spherical optical elements, a reflective point diffraction interference system based on micro polarizer array is proposed in this work. The interference system uses a short coherent laser source to obtain two coherent beams. The contrast of interference fringes is adjusted by adjusting the light intensity ratio of two polarized beams. Four phase-shifting interferograms are obtained by a single frame image collected by a CCD camera with integrated micro polarizer array to realize dynamic detection. The measurement results of the same concave mirror sample with the interference system and ZYGO interferometer are consistent, which verifies the accuracy of the measurement results of the interference system. On the experimental measurement platform, the vibration condition of the motor is added, and the results show that when the vibration velocity is less than 16 μm/s, more accurate surface shape measurement results can be obtained, which indicates that the anti-vibration performance of the interference system is good.