Research On Replication Technology Of Phase Holographic Reticle

Phase-type holographic reticle is a new type of reticle with surface relief structure,which is based on the existing holographic reticle and combined with the rapid development of micro-nano optical theory and microelectronic technology.Besides the advantages of light weight,high precision and good concealment,it has high diffraction efficiency,stable performance and can be reproduced and processed.It has good application prospects.In this paper,theoretical and experimental studies on the design and fabrication of mold microstructures are carried out for the replication of phase holographic reticle,and on this basis,replication experiments are carried out.The main research contents and results are as follows:Firstly the design principle of phase holographic reticle was described,and the phase structure of the holographic reticle was designed.The minimum characteristic size of the microstructures was determined to be 32.9?m.The simulation of the phase holographic reticle with 2,4,8,16 and 32 steps was realized,The contour distribution of relief microstructures on the surface of reticle with different steps and the height data of steps were obtained,and the quality of the reconstructed images was compared and analyzed.The results showed that the quality of the reconstructed image would be better and better with the increase of the number of steps,but the quality of the reconstructed image would be basically stable when the number of steps reaches a certain number.Secondly,the surface relief structure of the four-step phase holographic reticle mold was designed,and the processing data of the mold microstructures were obtained.According to the existing equipment,a four-step holographic reticle phase structure replication mold was fabricated by using single-point diamond fast tool servo processing technology.The surface microstructure of the mold was measured by white-light interferometer.The results showed that the surface profile of the micro-structure had a four-step cone shape.Then,according to the characteristics of phase structure of holographic reticle,the filling and demoulding principle of polymer in the process of embossing was studied by UV-curing nanoimprinting technology.The effects of different pressures,different polymer viscosities and different duty cycles on the filling process and the effects of polymer adhesion on the demolding process were simulated.Finally,three kinds of monomers marerials,?-mercaptopropyl trimethoxysilane,Ethylene Glycol Dimethacrylate and 2,2-Dimethoxy-2-Phenylacetophenone,were mixed in a ratio of 7:5:1.2 as UV-curable polymers to replicate the surface microstructures of the phase-type holographic reticle.The transmission rate of the replicated sample in the visible band was 87.03%,The reproducing optical path was set up to reproduce the replicated sample,and a clear reproducing image was obtained,and the error in the whole design and processing was analyzed.