关于光学元件面形评价参数峰谷值(PV)的分析

 光学元件的表面面形或波前质量一般采用数字指标峰谷值PV(表面最高点和最低点之差)来评价。而两点PV在高分辨率干涉仪的测量结果中具有很大不确定性。为了更准确地评价光学元件的表面面形或波前质量，讨论了针对两点PV进行改进后的评价方式PV20，PVr，PVq。通过模拟实验证明其可以描述真实波面，并在实验中证明其可以消除灰尘等杂点对测量结果带来的干扰，以及这几种评价方式对CCD分辩率的变化不敏感，并发现上述3种方式在测量重复性方面也有较好的表现。

Peak-to-valley parameter of optical component

 Peak-to-Valley departure (PV) is a widely used parameter in evaluating the quality of optical surface and wavefront. However, there is great uncertainty in optical surface testing using high resolution interferometer. In order to evaluate the quality of optical surface and wavefront more precisely, PV20, PVr and PVq are discussed. Through numerical simulation and experiment, it is proved that these three parameters can not only represent the real optical surface, but also be insensitive to interferometer spatial resolution. In addition, they have great advantage in metrology repeatability, hence, PV20, PVr and PVq are better than PV for characterizing optical surface.