Design method of a liquid crystal based computer-generated hologram for freeform surface measurement

Computer-generated hologram (CGH) is an essential component for aspheric and freeform surface measurement in the interferometry. Traditionally, CGH is manufactured by photolithography which is costly and time-consuming. A novel liquid crystal CGH and the design method based on the birefringence properties of LC and photo-alignment technology is presented in this paper. Simulation shows that this is a simple and reliable CGH design method which is appropriate for freeform interferometry test.