三维光子晶体红外隐身材料特性

The development and application of infrared stealth materials have attracted strong attention in the world with the rapid development of infrared detection technology in recent years. Photonic crystals stand out because of the adjustable band gap. Using photonic crystals with band gap in the infrared band as surface coating material can effectively change the infrared radiation characteristics of the target and achieve infrared stealth effect. The physical theory and experimental verification are combined to study the preparation of opal-type photonic crystal infrared stealth materials based on the self-assembly technology of colloidal elements, which provides theoretical guidance and technical support for the development of new infrared stealth materials. According to the Bragg diffraction law, the diameter ranges of the colloidal photonic crystal element with the band gap in the detection bands (3 - 5 μm and 8 - 14 μm) of the infrared detector and the infrared night vision device are determined respectively. The 1 - 2.21 μm colloidal polystyrene element with good monodispersity is synthesized by dispersion polymerization. Three commonly used colloidal element self-assembly approaches are studied: vertical self-assembly method, gravity sedimentation method and layer-by-layer self-assembly method. A constant-temperature water bath baking method is proposed. The experiments show that the opal-type photonic crystal prepared by this method has regular structure, and the infrared transmittance in the band gap range can be reduced from 80% to 25% . The infrared thermal imager test shows that the background material at 60 ℃ has good infrared stealth effect. The proposed method has the advantages of being applicable to multiple types of microspheres, short preparation period (only 3 h), simple preparation equipment and process, and high array regularity.