New Method to Produce Synthetic Holograms for Wavefront Generation.

Synthetic holograms are useful for interferometric testing of optical surfaces. In principle any aspheric wavefront may be generated. To avoid phase distortions, very severe requirements on the geometric accuracy of the computer-calculated and plotted hologram have to be met. Here, a new device is presented which has several advantages compared with methods used before: it is fast, rather inexpensive and offers a high geometrical precision. The quality of these holograms has been verified by interferometric measurements.