Fano resonances in high-index dielectric photonic structures

We reveal new and remarkable manifestations of the Fano resonances in high-refractive-index all-dielectric photonic nanostructures. First, we revisit the conventional problem of light scattering by an infinite dielectric rod and observe the existence of cascades of Fano resonances in the optical cross-section, which we investigate both numerically and analytically. Our analytical study is based on the exact Mie solution of Maxwell's equations for the light scattering by spatially homogeneous bodies of revolution. Next, we study the photonic bandgap structure and transmission spectra of two-dimensional square lattices of dielectric circular rods. We vary the refractive index of the rods from low to high values and observe a remarkable manifestation of a novel type of Fano resonances arising due to interplay between the resonant Mie scattering from individual rods and the Bragg scattering from the photonic lattice.