Chiro-optical response in helically arranged achiral dielectric nanoparticles

Abstract

We demonstrate experimentally how achiral dielectric nanoparticles when arranged in a chiral geometry can exhibit chiro-optical activity. Such a response originates in the dynamic electromagnetic interactions between the resonant modes of the individual nanoparticles, as confirmed by numerical simulations. When such nanoparticles are extended into an infinite periodic array, additional chiro-optical bands were induced at the lattice/collective modes of the nanoparticle system which have been experimentally observed. Our fabrication method is wafer scale and the material platform is low loss and CMOS-compatible, which together can allow a seamless integration of this novel material system into existing optoelectronic technologies.