Research On The Stealth Performance Of Flexible Thin Film Materials Based On Photonic Crystal Structure In Typical Application Situations

With the continuous development of detection technology,targets often face the risk of multi-band reconnaissance,so the use of multi-band compatible stealth is an important means to protect our targets.In this paper,we further investigate multi-band stealth films based on photonic crystal structures,which mainly include the following aspects.To address the problem that the multi-band compatible stealth performance of photonic crystal stealth film needs to be further improved,this paper designs a photonic crystal structure for visible,thermal infrared and 1.06μm laser compatible stealth by heterogeneous structure method,and prepares the structure by electron beam evaporation coating.Then conducting performance tests and analysis on the prepared film,the results show that the prepared photonic crystal film exhibits yellow,green and blue colors in visible and can achieve integration with the background of desert,grass and ocean in the visible band;the film has high reflectivity in the mid and far infrared bands,which can effectively suppress the radiation of the target in the mid and far infrared bands;the film has low reflectivity at 1.06μm wavelength,which can reduce the return power of the laser at this wavelength.To address the problem that ordinary flexible photonic crystals can’t be used normally when the target’s temperature is above 140°C,this paper firstly optimizes the photonic crystal film system and adopts the method of increasing the emissivity of5-8μm band to enhance the heat dissipation performance of the photonic crystal film,the optimized photonic crystal film has a lower equilibrium temperature compared with that before optimization.Then plating the photonic crystal structure on the high temperature resistant substrate material to obtain the high temperature resistant photonic crystal stealth film,the heat-resistant temperature is increased by more than 220°C,by treating the surface of the flexible substrate material to enhance the temperature-resistant performance of the flexible substrate material,and plating the photonic crystal structure on this material to obtain a high-temperature-resistant flexible photonic crystal film,the heat-resistant temperature is increased by 120°C,while maintaining good flexibility.To address the problem that environmental radiation has a great influence on the use of stealth materials,this paper establishes a typical environmental radiation calculation model to obtain the optimal emissivity of stealth films in typical application scenarios,and verifies the accuracy of the calculation model through experiments in some environments.The application of photonic crystal stealth films on the surface of vehicle engine compartments is investigated,and the results show that photonic crystal films have better results in mid-and far-infrared stealth compared with ordinary low-emissivity films.