In this days, OSA Continuum journal publishes a paper entitled as “Adjustable large-area dielectric metasurfaces for near-normal oblique incident excitation”
Abstract: We present large-area (25 cm2) dielectric metasurfaces based on silicon photonic crystal slabs. Adjustment of the slab thickness allows to systematically shift the metasurface resonances over several hundreds of nanometers. We compute the three-dimensional field energy density near the surface and determine optimum slab thicknesses for selected near-infrared excitation wavelengths applied in biophotonics. We explain this behaviour via the coupling of external radiation with symmetryprotected bound states in the continuum. These results enable metasurface-enhanced spectroscopy on large areas and underline the benefit of slight oblique incidence excitation conditions.
