Absolutely Testing of Off-Axis Aspherical Mirror Using Dichotomy Computer-Generated Holograms

Abstract

A method for absolutely testing off-axis aspherical mirror is presented. A dichotomy CGH including two zones on one substrate is designed. One sub aperture generates the spherical wave front that is used for calibrating the pattern errors of the hologram; the other sub aperture reconstructs the aspherical wave front to test the off-axis aspherical mirror. By means of known absolute interferometric methods, the aberrations of the calibration wave front can be obtained. These aberrations can be transferred to the null testing wave front. The testing method is explained and the dichotomy CGH is designed. Finally, a simulation result supports this absolutely testing method.