Study on preparation process of high diffraction efficiency liquid crystal computer generated hologram

Computer-generated hologram (CGH) method is a high-precision aspherical surface detection method. CGH produces wavefronts of any shape with extremely high precision and is adopted in null test. Liquid crystal CGH (LC-CGH) is a new type of CGH with short production cycle and low cost. It is a promising alternative to traditional CGH. In this paper, the overall process flow of LC grating preparation is presented. The influences of three process parameters, such as LC solution concentration, spin coating speed and time on the three physical quantities of LC grating diffraction efficiency, LC polymer film thickness and phase delay are studied. Based on the analysis, improvement measures are proposed for the preparation process. The research carried out in this paper has guiding significance for the processing and manufacturing of LC-CGH.