van der Waals metasurfaces based on hyperbolic-medium antennas

Abstract

Optical antennas made out of van der Waals material with naturally occurring hyperbolic dispersion is a promising alternative to plasmonic and high-refractive-index dielectric structures in the practical realization of nanoscale photonic elements and optical components. Here we show that antenna made out of hexagonal boron nitride (hBN) possesses different resonances enabled by the supporting high-k modes and their reflection from the antenna boundaries. Multipole resonances cause the decrease in the reflection from antenna array to zero, which can be ascribed to resonant Kerker effect satisfying generalized zero back-scattering condition for particles in the array. Reflection and transmission through the van der Waals heterostructure with hBN antennas array can be tailored and actively switched by tuning optical properties of two-dimensional materials. Transdimensional photonic lattices consisting of resonant hBN antennas in the engineered periodic arrays have great potential to serve as functional elements in ultra-thin optical components and photonic devices.