Metasurface mirrors based on homogeneous materials for high-power lasers

Abstract

Low-loss and high-reflection mirrors have important applications in high-power laser systems. Conventional mirrors based on multilayer films are damaged by thermal distortion between the layers when irradiated by high-power lasers. In 2022, H. Atikian et al. designed and demonstrated a dielectric metasurface mirror for high-power continuous-wave lasers with a bandwidth of 10 nm and a reflectance of 98.9 ± 0.3% by etching nanostructures into the surface of single-crystal diamond to overcome the limitation of coating defects. We optimize the structure to achieve a broadband high reflection of 100 nm with 99.88% average reflectance. Furthermore, we extend the structure to other typical optical materials to achieve high reflection, such as silicon, alumina, and silicon oxide and find that relatively high refractive index is important to realize broadband high reflection. Our work provides a reference for the design of homogeneous material-based metasurface mirrors operating under high power conditions.