Efficient directional control of scattered field at optical frequency with subwavelength asymmetric dielectric dimers

Abstract

High refractive index dielectric nanoparticles are promising as a complementary nanophotonics platform due to low absorption losses and the co-existence of magnetic and electric resonances when compared with plasmonic nanostructures. Here we demonstrate that finely designed asymmetric dimer configurations of silicon nanoparticles can switch the direction of scattered electromagnetic field depending on the incident wavelength and/or polarization. This is due to the interference between electric and magnetic dipoles excited in each nanoparticle. The application of the proposed asymmetric nanoantennas is also explored as a light guiding block in optical nanocircuitry.