Double grating phase stepping interferometry for testing aspherics

被引：7

作者：

Betend-Bon, Jean-Pierre ^{[1
]}

Wosinski, Lech ^{[1
]}

Breidne, Magnus ^{[1
]}

机构：

[1] Inst of Optical Research, Stockholm, Sweden

来源：

Pure and applied optics | 1992年 / 1卷 / 01期

关键词：

Diffraction gratings - Integral equations - Interferometry - Mirrors;

D O I：

10.1088/0963-9659/1/1/006

中图分类号：

学科分类号：

摘要：

In order to increase the dynamic range of shape measuring interferometry, a double-grating shearing interferometric technique has been developed. The interference takes place between two wavefronts diffracted from two high density sinusoidal gratings. Phase stepping by means of lateral shifting was introduced to obtain automatic fringe analysis. The surface shape is reconstructed from the first derivative of the phase distribution with the assumption of a rotationally symmetric object. This assumption is reasonable for testing diamond-turned surfaces. The measurement accuracy depends upon the surface size and the shear amount. We experimentally measured a spherical diamond-turned mirror shape with an accuracy of λ/2 (λ = 0.6328 μm), and a theoretical dynamic range of hundreds of λ.

引用

页码：55 / 69