Substrate calibration method of a computer-generated hologram based on ray propagation in a three-dimensional model

In interferometry with a computer-generated hologram (CGH), the substrate error of the CGH limits its high-precision aspheric measurement application. The propagation form of the substrate error is still ambiguous although 0th-order calibration can partly correct it. We established the ray propagation in a three-dimensional model in order to solve the ambiguity of substrate error propagation. This method shows the modulation process of the CGH substrate error on the transmitted wavefront for the first time, until now, to the best of our knowledge. The experiments show that the propagation of the substrate error can be accurately analyzed, and the CGH design efficiency also is significantly improved after applying this method.