Optimization Method of Wavefront Reconstruction Based on Spatial Light Modulator

Abstract

To measure the aspheric surface, the reconstruction of the reference wavefront based on spatial light modulator (SLM) is studied in this paper. Computer-generated hologram (CGH) interference encoding method has been selected and the hologram is been loaded into the SLM to reconstruct standard wavefront. The principles of wavefront reconstruction and the experimental system are introduced at first. Considering the effect of the SLM grid structure on wavefront accuracy, the optimization methods are proposed. With the use of 4f spatial filtering system, the multiple diffraction patterns due to the effect of the SLM grid structure can be removed. The reconstruction wavefront based on dislocation superposition method is used to reduce the impact of black grid. The analysis result shows that the quality of reconstruction wavefront has been improved effectively through the optimization methods.