Study on four-step computer-generated hologram with same diffraction efficiency of the zeroth and first order

摘要

A type of computer-generated hologram (CGH) with 4-step mi-crostructure is designed based on diffraction theory. Results show that this CGH has almost the same diffraction efficiency at zeroth diffractive order and positive first diffractive order, which are 38.51% and 38.04%, respectively, and the intensity of these two beams is 76.55% of incident beam. This type of 4-step CGH can be used in an off-axis convex aspherical mirror interferometric system with double CGHs, while the signal-to-noise ratio (SNR) of the interferogram is high enough.