Computer-generated Holograms for Testing Optical Elements: Error Analysis and Error Compensation

When generating wavefronts by synthetic holograms several sources of error have to be considered. In this paper two sources are analysed. The first is the binarization of the hologram structure; a quantitative estimate is given for two typical cases. The second is distortion caused by the graphic device applied to generate the hologram diagram. Several techniques in recording and compensating for these errors are described. It is shown that a dual synthetic hologram exhibits special advantages. A compromise has to be made in reducing both of these errors. Reducing the errors caused by binarization increases errors caused by distortions in the hologram diagram and vice versa.