Experimental Study Of Reflection Film On The Surface Of Tetrahedral Optical Elements

With the market demand for high imaging quality,wide field of view,large band and light weight of the reflector system,tetrahedral optical elements emerge.However,due to the high integration of the integrated component,it has a complex structure,and the existing coating machine can not directly finish coating on it,so how to deposit uniform and durable high reflection film on its surface has become an important problem.In order to obtain high reflectivity of the film,the silver series high reflectivity film was designed,and the magnetron sputtering technology was qualitatively explored on the sample of integrated components.In order to make the film deposition uniform,the film thickness distribution model was established,and the model was used as the basis for the modification of the existing film coating machine.The position relationship between the target material in the vacuum chamber of the film coating machine and the sample workpiece was improved.In order to investigate the durability of the film,nano indentation,scratch experiment and finite element simulation were used to study the Membrane adhesion of the film.Firstly,the structure and thickness of the film were optimized by optical design software,and a highly reflective silver film with a protective layer,a reflective layer and a transition layer was designed,and the influence of incident Angle on the reflectivity was investigated.The effects of different power,working air pressure and basic pressure on the film reflectivity were investigated.Secondly,the thickness distribution model of magnetron sputtering film was established,and the effects of the type of target material,the dip Angle of substrate and time on the film thickness uniformity were analyzed,and the position relationship between the target material and substrate was optimized.Orthogonal experiments were designed,and the order of influence of power,air pressure and rotating speed on film uniformity was determined by SNR analysis,and the optimal level combination was selected.The correlation between surface type and film uniformity was studied by variance analysis.Finally,the finite element models of nano indentation and scratches of the high reflective film were established,and the accuracy of model was verified by several groups of nano indentation experiments.The bonding strength of the high reflective film was analyzed by the nano indentation experiment and finite element simulation technology.The cross section and the material state of each layer were characterized by TEM analysis.