FROST-PREVENTION FILM SYSTEM OF LARGE-APERTURE REFLECTING TELESCOPE USED IN EXTREMELY LOW TEMPERATURE ENVIRONMENT AND PREPARATION METHOD THEREFOR

摘要

A frost-prevention film system of a large-aperture reflecting optical infrared telescope used in an extremely low temperature environment and a preparation method therefor. The frost-prevention film system has the following structure: a transparent conducting film layer (2), an intermediate insulation layer (3), a reflecting film layer (4) and an outermost medium protection layer (5) in sequence from a main telescope surface, wherein both sides of the transparent conducting film layer (2) are provided with conducting electrodes (6). The steps are as follows: (1) a preparation step; (2) a step of plating a conducting film layer (2); (3) a step of plating an intermediate insulation layer (3); (4) a step of plating a reflecting film layer (4); (5) a step of plating an outermost medium prevention layer (5); and (6) a step of plating conducting electrodes (6). The present invention can be used in an extremely low temperature environment, combined with telescope surface temperature rise to control and avoid the frosting of a telescope surface; and the structure of the frost-prevention reflecting film system is rationally designed, thereby guaranteeing the spectral reflection performance of the film system while having the function of frost prevention.