Reflection suppression by the hyperbolic-medium antennas and silicon particles

TL;DR

This paper investigates hyperbolic-medium antennas and silicon particles arranged in arrays to suppress reflection by overlapping electric and magnetic resonances, enabling efficient forward scattering for mid-infrared applications.

Contribution

It demonstrates how combining hyperbolic-medium antennas with silicon particles can achieve reflection suppression through resonance overlap, advancing metasurface design.

Findings

Reflection decrease achieved with specific particle dimensions

Electric and magnetic resonances overlap for phase matching

Enhanced forward scattering in the array

Abstract

Optical antennas made out of materials with hyperbolic dispersion is an alternative approach to realizing efficient subwavelength scatterers and may overcome limitations imposed by plasmonic and all-dielectric designs. Recently emerged natural hyperbolic material hexagonal boron nitride supports phonon-polariton excitations with low optical losses and high anisotropy. Here we study scattering properties of the hyperbolic-medium (HM) antennas, and in particular, we consider a combination of two types of the particles - HM bars and silicon spheres - arranged in a periodic array. We analyze excitation of electric and magnetic resonances in the particles and effect of their overlap in the array. We theoretically demonstrate that decrease of reflectance from the array can be achieved with appropriate particle dimensions where electric and magnetic resonances of different particle types overlap, and the resonance oscillations are in phase. In this case, generalized Kerker condition is satisfied, and particle dimers in the array efficiently scatter light in the forward direction. The effect can be used in designing metasurfaces based on hexagonal boron nitride scatterers with an application in mid-infrared photonics.