Φ2 m平面反射镜低频轮廓非接触测量设备研制进展  

Development progress of instrument for low-frequency non-contact profile measurement of Φ2 m flat reflector

作　　者：何煦[1] 

机构地区：[1]中国科学院长春光学精密机械与物理研究所,吉林长春130033

出　　处：《应用光学》2016年第1期80-86,共7页Journal of Applied Optics

基　　金：国家自然科学基金(61307114)

摘　　要：口径2m的高质量平面反射镜可用于大口径光电设备像质评价和性能检测,但受使用环境影响,平面反射镜的面形精度不易长期保持稳定,因此需要在使用前对其面形精度进行现场、快速校验,而常规的全口径或子孔径干涉检测均难以满足上述需求。由于反射镜面形在制造过程引入的中高频误差已处于稳定状态,环境扰动只引入低频像差,而选择子孔径斜率扫描再重构波面低频轮廓的方法较适于面形精度现场校验。提出双五棱镜配合双测角仪进行子孔径斜率同步差分测量的方法,可改善长测量周期内环境扰动引起的随机误差。并对测量设备光学、机械及控制系统进行设计,提出采用2台S-H传感器代替传统测角仪用于子孔径斜率测量的解决方法。验证试验结果表明,波面重构算法以及仪器测角精度可满足面形测量精度需求,其与ZYGO干涉仪测量结果的互差小于20nm(RMS)。The high-quality flat reflector with 2 m aperture can be used for image quality evalua- tion and performance testing of large-aperture optical instruments. However, by the impact of usage environment, the surface accuracy of large flat reflector cannot maintain long-term sta- bility. Therefore, the surface quality needs to fast calibration on site before using. But the conventional full-caliber or sub-aperture interferometry measurement methods are difficult to meet these needs. Due to the high frequency error of mirror introduced in the manufacturing process being in a steady state, the environmental perturbations introduce only low frequency aberrations. And the selected reconstructed wave-front profile followed with sub-aperture slope scanning is more suitable for surface quality calibration on site of large flat reflector. A double-pentaprism with dual-goniometer synchronize differential measurement method was proposed, which could reduce the random error caused by environmental disturbances in long measurement cycle. Moreover, the optical, mechanical and control system of measurement instrument was designed. And two S-H sensors were proposed to use to instead of traditional goniometer for sub-apertures slope measurement. Currently validation tests show that the wavefront reconstruction algorithms and instrument angular accuracy meet the demand of accuracy for surface quality, the mutual difference is less than 20 nm （root-mean-square,RMS） with the test result of ZYGO interferometrie measurement.

关 键 词：大口径平面反射镜 面形精度 轮廓测量 子孔径波面斜率 

分 类 号：TN247[电子电信—物理电子学]