共光路外差干涉法精密测量光学表面

报道了光学外差法测量表面起伏精度及横向分辨精度达到０．１１ｎｍ及４μｍ。本文采用的是完全共光路外差干涉系统，阐述了它的原理、构造及噪声的影响，并将测量结果与其它商品仪器测量结果作了比较。

Precision evaluation of a common-path interferometer in measurement of optical surfaces

An optical heterodyne profiler has been developed for measuring surface roughness. The height measurement accuracy and lateral resolution are 0. 11 nm and 4 μm, respectively, when a 40× objective is used. A Zeeman-split He-Ne laser is used as the light source. The optical system is designed as a completely common-path interferometer. Optical and electronic common-mode rejection techniques are employed to minimize the effects of environmental conditions. Sample measurements by this heterodyne profiler and other commercial profilers are displayed. The system noise effect is analyzed in detail, the effect of varying the number of samples at each sampling point is shown. The accuracy comparisons of the profiler with different objectives 5×, 10×, 20× and 40× are presented.