Design of High-Efficiency Circularly Polarized Reflection Mirror Based on Chiral Dielectric Metasurface

Circularly polarized lasers can directly generate circularly polarized light without requiring complex external optics, enabling applications in biosensing, environmentally friendly antibacterial treatments, and cancer cell phototherapy. However, the circular dichroism (CD) of chiral metasurface mirrors—a core component of such lasers—typically remains below 3%, limiting beam quality. Using COMSOL simulations, we broke the metasurface’s structural symmetry via displacement and rotation operations, introducing chirality to the unit cell. At 980 nm, the metasurface achieved 99.85% reflectivity and 52% CD. Multipole analysis suggests this enhancement stems from electric dipole and quadrupole coupling. Our laser design could generate micro-nano-scale chiral light, advancing applications in biophotonics, biomedicine, and life sciences.