Fabrication Of Holographic Optical Elements Based On Laser Aiming

As the core component of the holographic sight system,the holographic optical element directly affects the performance of the holographic sight.However,the diffraction efficiency of the currently prepared holographic optical element is low and the experimental environment is harsh,and the post-processing process is a complicated wet chemical treatment.Based on the holographic interference exposure technology,in-depth research on the preparation process of the holographic optical element of the holographic aiming system has certain research value for improving the performance of the entire holographic sight and the optimization of the preparation process.This paper focuses on the preparation of holographic optical elements suitable for transmission h olographic sight systems,including transmission volume holographic gratings and holographic aiming reticle.Firstly,the recording and reproduction mechanism of the holographic aiming reticle is analyzed.The formation process of the volume holographic grating as well as the recording process and the reproduction process,are established to analyze the related mathematical models.The modulation of the incident light beam by the transmissive volume holographic grating is simulated based on COMSOL software,which is consistent with the modulation of the incident light beam in the theoretical design processAccording to the experimental parameters,the effects of the refractive index modulation of the recording medium,the thickness of the grating film,and the Bragg shift on the diffraction efficiency are simulated which provides the theoretical guidance of the preparation process of holographic.Secondly,based on the holographic interference technology,and a photopolymer holographic recording materials based on(PVA/AA)system are prepared.the volume holographic grating and the holographic aiming differentiation plate suitable for the holographic sight system are prepared by designing and building the holographic exposure light path system.The process parameters of the preparation process and post-processing of the holographic optical element are determined.The holographic reconstruction verification experimental system was designed and built.The verification showed that the prepared holographic optical element can be used in the holographic aiming system,and the beam diffracted into a clear holographic aiming reticle pattern after passing through the holographic optical element.Finally,by building a volume holographic diffraction grating test device,the diffraction efficiency of the transmission volume holographic grating and the first order diffraction angle is tested.And an experimental study is conducted on its influencing factors.The transmission hologram can be obtained after the total power of the interference beam of 0.75 mW,the drying time of 3 h,the exposure energy of 135 mJ/cm~2,the ultraviolet curing time of 15 s,the drying temperature of 90℃,and the drying time of 30 min.The diffraction efficiency of the diffraction grating can reach 82.57%.It has certain reference significance for the preparation process of subsequent experiments.