Enhancement of second-harmonic generation through Brillouin zone folding in a waveguide-coupled metasurface.

ABSTRACT: Metasurfaces have become significant platforms for optical manipulation, yet unlocking their full potential for nonlinear optics requires novel mechanisms to control and enable frequency conversion processes. This study demonstrates how structural dimerization in plasmonic metasurfaces coupled to waveguides can modify linear and nonlinear optical behavior via Brillouin zone folding. By introducing a centrosymmetric unit cell design featuring two mirrored split-ring resonators, we allow guided modes that were previously below the light line to appear as guided-mode resonances. These resonances facilitate nonlocal modes, which are present as distinct narrow transparency windows. Although centrosymmetric dimerized design typically forbids far-field radiation through quadratic nonlinear intera

SUBMITTER: Abir T 

PROVIDER: S-EPMC12442358 | biostudies-literature | 2025 Sep

REPOSITORIES: biostudies-literature