Development Of Wavelength Separation Coating In 1064nm Laser And Far-infrared Common-window Imaging System

In order to improve the ability and precision of military investigation,the technology of infrared detection and imaging which is multi-band and more-active has become the current research hotspot.According to the requirements of the laser and far infrared common-window imaging system to adjust the energy proportion of laser?1064nm?and far infraredwave?8¹4?m?,using ZnS and YbF₃ as coating materials,a wavelength separation coating is designed,that is,1064nm laser reflected,8¹4?m far infrared light transmitted.The influence of material absorption on membrane system was studied by means of inverse inversion,and the transmittance of far-infrared band was improved..By analyzing the microstructure of the films,the refractive index changes of the films before and after moisture absorption were studied.The structure of the films was optimized by combining the optical film theory.On the basis of studying the stress of the film,the film thickness was optimized and the film firmness was improved.The average transmittance of the wavelength separation coating in the bands of 8¹2?m?12¹4?m are 97.1%?90.1%and the reflectivity of 1064 nm is 99.71%.The separation coating can meet the technical requirements of the imaging system for a long time in various military outdoor environments.