The Design of Highly Reflective All-Dielectric Metasurfaces Based on Diamond Resonators

All-dielectric metasurfaces offer a low-loss alternative to plasmonic metasurfaces. We proposed the configuration for high-reflectivity all-dielectric metasurfaces based on single-crystal diamond (SCD) resonators on fused silica substrate and conducted simulations to optimize and analyse such configuration via FDTD solver. We utilized GMR as design principles to select the configuration and the substrate material, and analyzed the scattering properties of a single SCD resonator by multipole decomposition. Then we have demonstrated that both the cylindrical resonators in square lattice and frustum-shaped resonators in hexagonal lattice can achieve near-unity reflectivity (> 99.99%) and ultra-low absorption (< 0.001%) at 795 nm, the typical alkali-metal laser wavelength. Additionally, we have demonstrated that such design is quite tolerant to fabrication errors and further supports its potential for realistic applications. To expand the functionality of such devices across multiple wavelengths, a dual-band high-reflectivity meta-surfaces at 744 nm and 828 nm has also been designed. Our work is quite useful for designing diamond-based highly reflective mirrors, paving the way for low-loss all-dielectric reflective metasurfaces in high-power laser applications.