Theoretical And Experimental Research On The Influence Of The Position And Wavelength Of The Illumination Light In The Holographic Sight On The Position Of The "cross" Image

Holographic sight(HS)is a new generation gun sight,and it is considered as a revolution product because of high precision,fast aiming speed and strong reliability.Nowadays,HS has been widely armed for troops in some countries.However,domestic research about HS is incomplete,product performance still needs to be improved.The core component in HS is holographic reticle which records reticle image for aiming,a laser diode is used to illuminate holographic reticle in most cases.Wavelength and position change will result in position deflection of reticle image,then reduce shooting precision of operators.To solve this problem,a holographic matching element is added into HS to construct imaging system with holographic reticle.The imaging systems in HS can be divided into two types—Fresnel imaging system and Fraunhofer imaging system.Mathmatic model about position of reticle image and illumination light is established,then numerical analysis based on mathematic model is accomplished.The result show that position of reticle image in Fresnel imaging system is influenced by positon and wavelength of illumination source,and position of reticle image can be independent with wavelength change if Fresnel holographic matching element is parallel with holographic reticle.And position of reticle image in Fraunhofer imaging system is influenced by angle and wavelength of illumination light,the influence can be minimized if the angle between holographic reticle and Fraunhofer holographic matching element is set appropriately.Experiment for measuring position deflection of reticle image in Fresnel imaging system and Fraunhofer imaging system is accomplished.Multidimensional optical adjusting rack and thermostat are used to adjust position,angle and wavelength of illumination light,then the position deflection can be observed through a diopter cylinder,experimental value fits theoretical value well.Performance of HS is determined by holographic reticle directly.Silver halide emulsion is used as recording medium of holographic reticle,modified AAC developer and R-10 bleach are used to process holograms after exposure in our experiment.Above technologies bring high transparency to holographic reticles and ensure their diffraction efficiency reach to 30%in working waveband.What's more,holographic reticles after encapsulation can keep stable for a long time in humid environment with temperature changing from—450C to 50? in our experiment.The project result can provide theoretical basis and reference for manufacture of devices used for adjusting azimuth of reticle image,and act as guide for design,manufacture,assembly,calibration and precision increase of HS.In addition,it is also helpful to domestic industrialization of HS.