Sphere dimers of high refractive index dielectric particles as elementary units for building optical switching devices

摘要

Semiconductors like Si, Ge (and other compounds like GaAs, GaP, etc) show high values of their refractive index and low absorption in the visible (VIS) and near-infrared (NIR) ranges. Nanoparticles made of these high refractive index (HRI) materials have been recently proposed as an alternative to metallic ones to overcome their inherent ohmic losses. In addition, the excitation of coherent electric and magnetic resonances makes these HRI nanoparticles to become basic to build multifunctional elements in optical devices for controlling the directionality of the scattered radiation. Here, we present unambiguous experimental evidence in the microwave range that a dimer of spherical High Refractive Index dielectric particles behaves as an elementary block for building switching devices whose binary state only depends on the polarization of the incident radiation. The corresponding analysis has been carried out by means of the linear polarization degree of the scattered radiation at the right angle scattering configuration.