Bioinspired Meta‐Reflection‐Splitter for Near‐Infrared Laser Stealth with Large Scattering Angle

Metasurface based phase manipulation has shown great capable of controlling anomalous reflection for low observability against laser active detection. However, current meta-based designs for laser stealth in near-infrared (NIR) range suffer from small scattering angles and complex fabrication process, and this hinders their mass productivity and flexible application in actual environments. Here, a bioinspired strategy is proposed to design a meta-reflection-splitter with a large scattering angle and strongly extinct specular reflection for NIR laser stealth, motivated by the color splitting effect on the green scale of butterfly Diaethria clymena. The biological reflection splitting is demonstrated to originate from the 180° phase difference of reflection created by the unsymmetrical laminae on densely arranged ridges. A simple etching-free approach is further developed to generate large-scale meta-reflector-splitter by self-assembly of colloidal particles. This large-area meta-reflector-splitter shows high-efficient low observability (ultralow specular reflectance <1%) accompanied by a scattering angle of nearly 50° under the 1064 nm laser detection as well as a low mid-infrared emissivity. This work sheds light on the phase manipulation of biophotonic structures and thus benefits the innovation in advanced optical materials and devices.