表面形貌测量在光学元件加工制造和表面功能特性评定等方面有着非比寻常的意义。设计一种三波长轮换的表面形貌测量系统, 与传统的白光相移干涉扫描等方法相比较, 能够有效扩大测量深度以及形貌精度。多波长测量中波长带来的误差会极大的影响测量的精度, 需要准确的校准波长。围绕三波长轮换表面形貌干涉测量系统, 提出了利用平面镜干涉图校准三个滤光片波长的方法。通过对粗糙度样本的测量实验及计算结果显示: 用校准后的波长计算标准方波样板得到的表面粗糙度数据与未使用为校准波长测得的结果相比其精度提高了1.3%, 与标准数据相比较其相对误差仅为4.1%。

Surface topography measurement is of great significance in the fabrication of optical components and the evaluation of surface functional properties. A three-wavelength surface topography measurement system is designed which is compared with the traditional white light phase shift interference, the multi-wavelength surface topography measurement system can effectively extend the measurement depth and the measurement accuracy of topography. Because the wavelength error in multi-wavelength interferometry greatly affects measurement accuracy, the wavelengths of light source is accurately calibrated. Based on the three-wavelength rotating surface topography interferometry system, A method for calibrating the wavelengths of three filters by using a planar mirror interferogram is presented. Through the measurement of roughness samples, the experimental results show: the surface roughness data obtained from the standard square wave pattern calculated with the calibrated wavelength was compared with the results measured using the original wavelength, the accuracy is improved by 1.3%, and the result was compared with the calibration data of China Academy of Metrology ,the relative error is only 4.1% .