Research Of Standard Wavefront Reconstruction Algorithm Based On Spatial Light Modulator

In the optical field, non-spherical optical elements have found wide applications the cause of its small size, low weight and high performances. However, the non-spherical technology has been largely restricted for itself testing methods, because it can not be achieved by a simple, efficient and quick testing process. In particular, the acquisition of the standard wavefronts corresponding to the different tested non-spherical surfaces is still a blind spot.The reconstruction of standard wavefront based on spatial light modulator (SLM) has been studied. Computer-generated hologram (CGH) interferograms encoding method has been selected to encode the hologram of the standard wavefront, according to the characteristics of different coding methods and SLM. The hologram has been loaded into the SLM and the standard wavefront is reconstructed. Considering the effect of the SLM grid structure, the method named stacking of dislocated messages of the grid structure has been proposed and simulated. The result shows that the quality of the reconstruction wavefront is improved. There are five parts in the paper.Firstly, the latest development of modern non-spherical testing technique is introduced, especially the acquisition of standard wavefront; secondly, the CGH interferometry and its basic principles are studied deeply and most researches focused on different coding methods of CGH. The holographic records are realized by different encoding methods; thirdly, the characters of standard wavefront holographic recording media-SLM have been studied, which include optical modulation characteristics, imaging characteristics and the mature applications. Then the encoding methods of standard wavefront reconstruction have been selected based on the characteristics of CGH; fourthly, experimental platform has been built to verify the feasibility; fifthly, the method of stacking of dislocated messages of the grid structure is addressed to improve the quality of the reconstruction wavefront and it has been simulated. The result shows that the RMS of the reconstruction wavefront is reduced nearlly 4.45 times. In the background of the non-spherical testing technology and CGH interferometry method, standard wavefront reconstruction methods have been analyzed and researched. It provides a reliable theoretical basis and experimental evidence for the acquisition of high precision standard non-spherical wavefront.