One dimensional photonic crystal based multilayer film with low IR and visible signatures

Abstract

A multilayer film with high reflection wavebands and specific visible appearance has been designed based on principles of photonic crystals and optical interference. The angle and thickness sensitivities of this film, which is fabricated with germanium and zinc selenide, were studied and discussed. This multilayer film possesses a high average reflectance between 3 and 5 μm (92.1%) and 8–14 μm (84.2%) wavebands, thereby contributing to a low emissivity in those wavebands according to Kirchhoff's law of thermodynamics. As a result, IR energy from a hot object covered with this film would be suppressed, and low IR signature is expected to be realized. Chromaticity diagram shows that the chromaticity coordinates of this film is close to those of real green plants, which will make it more difficult to distinguish this film from green plant background. Combining the above features, this photonic crystal based film is promising to realize low IR and visible signatures under appropriate conditions.