大口径大曲率半径光学元件的高精度检测

High-precision metrology for optical components with large-apertures and large radii of curvature

针对目前已有的光学检测设备无法实现大口径大曲率半径光学元件高精度检测的问题,提出利用长程轮廓仪(LTP)来进行大口径大曲率半径(正、负)光学元件的精确测量,并通过实验证明了LTP检测大曲率半径光学元件的优势。分析计算了LTP测量曲率半径的算法精度,设计了合理的机械结构进行旋转测量,得到了全口径的曲率半径分布。最后与球径仪、刀口仪的测量结果进行了对比。对R=37.108m和R=41.065m的球面镜测量结果显示,LTP的测量重复性在0.05%以内,与球径仪、刀口仪的测量值相差均在0.05%以内。研究结果表明,LTP可以用来解决目前几十米的大R曲率半径光学元件难以高精度测量的难题。

For lack of proper metrologic instruments to measure optical components with large-apertures and large radii of curvature,this paper investigates the feasibility to measure large radius of curvature（positive,negative） by using a Long Trace Profiler（LTP）.The experiments are carried out to verify its advantages.The algorithmic precision of radius of curvature tested with the LTP is calculated,then the radius of curvature of full-aperture is figured out by a rotational measurement in a proper mechanical stage.Finally,obtained tested results are compared with those of a spherometer and a knife-edge tester.For the spherical surface with R=37.108 m and R=41.065 m,the repeatability of the LTP is in 0.05%,which means the relative discrepancy between the LTP and the spherometer or the knife-edge tester is under 0.05%.These results indicate that LTP is capable of measuring components with large radii of curvature in high-precision.