衍射光学元件表面形貌测量方法研究

Investigation on Measuring Method for3-D Surface Topography of Diffractive Optical Elements

提出了一种基于双光路双波长相移干涉显微原理的新型 DOE三维表面形貌测量方法 ,并建立了相应的测量系统。理论分析和测量结果表明 ,测量系统纵向分辨率为 0 .5 nm,横向分辨率约为 0 .5 μm(NA=0 .4) ,在整个纵向测量范围内重复测量精度优于 1 .3nm,满足了 DOE表面形貌测量的需要。

Based on dual- light- path and dual- wavelength phase shift interference microscopic principle,a novel measuring method,which can be applied to the measurement of3- D surface topography of diffractive optical elements,is proposed and a corresponding measuring system has been setup.The theoretical analysis and measuring results show that the longitudinal resolution of the system is0 .5 nm and the transverse resolution is about0 .5 μm(NA=0 .4) .The repeated measuring accuracy within the whole longitudinal measuring range is better than1 .3nm.This fulfills the demands for surface topography measurement of DOE.