Optimization and preparation of a visible-infrared compatible stealth film based on D/M/D structure

Abstract

It is difficult for current camouflage coatings to realize visible-infrared-compatible stealth. To solve this problem, we develop a film based on a dielectric/metal/dielectric (D/M/D) structure, which shows a high visible (0.4 ∼ 0.8 μm) transmittance and a high infrared (3 ∼ 14 μm) reflectance (i.e., low emittance). When applied on a camouflage coating, because of the high visible transmittance and low infrared emittance of the film, visible-infrared-compatible stealth can be realized. The thickness of each layer of the ZnS/Ag/ZnS film is designed using the particle swarm optimization method. By thermal evaporation, this film is prepared on a quartz glass substrate with an average visible transmittance and infrared reflectance of 89% and 95%, respectively. According to the angle-dependent relationship of the spectral properties, both the visible transmittance and infrared reflectance are above 80% within a 60° oblique incident angle. The visible reflectances of the sample on sandy and yellow-green camouflage coatings confirm the compatible visible stealth, while the radiative temperatures obtained by two thermal infrared imagers within the temperature range of 25 ∼ 150 °C demonstrate infrared stealth performance.