Research On Laser Protective Thin Film With Visible Light Stealth Function

Laser weapon,as a new type of weapon,has been developing for a period of time.With its advantages of strong activity ability,being able to adapt to a variety of battlefield environments and lower cost compared with traditional weapons,laser weapon has occupied an increasingly important position in the modern war of informationization.Correspondingly,how to design and prepare laser protective film with high protection efficiency and can meet a variety of attack conditions has also become the focus of attention.The traditional laser protective film is mainly made of equal-phase change materials,which will change from semiconductor state to metal state at high temperature.The high reflectivity of metal is used to reflect the laser to achieve the purpose of protection.The main problem with this method is that the phase transition requires time to respond quickly to the laser,and the protection Angle is small,so it cannot adapt to the changeable environment of the battlefield.To solve this problem,a laser protective film based on omnidirectional reflection is proposed in this paper.Omnidirectional reflection mainly makes use of the band gap characteristic of onedimensional photonic crystal,which can’t propagate the incident light of a specific wavelength,so it can achieve high reflection for the incident light of that wavelength from all angles.In this paper,an 11-layer high reflector membrane for 1080nm was designed by using a regular membrane system based on 1/4 wavelength.The simulation results show that the designed film system has more than 99%reflectivity at 1080nm,and it can also maintain good reflectivity to large Angle incident light.Because the combat environment of laser weapon is diverse,and at the same time,the laser shield film is designed with visible light stealth function in this paper.Specifically,according to the People’s Republic of China Military Standard Camouflage Coating Color,the emerald green laser protective film for the forest environment and the sand color laser protective film for the desert environment are designed.The optimized design of the film system can present the target color well through simulation experiments.In this paper,according to the green laser protective film system designed for forest environment,the protective film was prepared by using the electron beam evaporation coating equipment assisted by ion source.Through experimental verification,the prepared film has good reflection performance at 1080nm and meets the color requirements.It can be considered that the designed protective film system has practicability.