High-index nanostructures and layered materials for light scattering control

Planar optical elements with efficient light control at the nanoscale can be designed based on transdimensional photonic lattices that operate in the translational regime between two and three dimensions. Such transdimensional lattices include 3D-engineered nanoantennas supporting multipole Mie resonances and arranged in the 2D arrays to harness collective effects in the nanostructure [1]. 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. The antenna made out of hexagonal boron nitride (hBN) possesses different multipole resonances enabled by the supporting high-k modes and their reflection from the antenna boundaries. The full range of the resonances is demonstrated for the hBN cuboid antenna, a decrease of reflection from the array, and highly directional resonant scattering from antennas pairs. We show that transdimensional 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. [1] V.E. Babicheva, MRS Advances 4, 713 (2019).