Extraordinary Optical Reflection from Annular Dielectric Nanorod Arrays

Responses of free standing subwavelength annular dielectric nanorod arrays are described. Extreme reflection peaks with high quality factor follow a multiple scattering approach, which can be explained by geometrical resonance. It is demonstrated that the value and the resonant frequency of the sharp geometric resonance modes can be tuned by geometric parameters such as the outer radius, inner radius of the annular nanorod array, and incidence angle sensitively, which can provide new regulating factors and guidance for the design of novel optical device using the dielectric material with a lower volume.