Directional Enhancement Analysis of All-Dielectric Optical Nanoantennas Based on SIE Formulation

Recent advances in optical nanoantennas made of high-permittivity low-loss dielectric particles have demanded efficient numerical modeling techniques for electromagnetic radiation and scattering simulations. Here, the facing requirements of fast convergence of iteration methods and good accuracy of results, a modified surface integral equation for high-permittivity objects has been presented. Moreover, based on the proposed surface integral equation, a full study of the dependence of the radiation pattern on the relative permittivity and wavelength has been performed for a single-dielectric nanoparticle with the excitation of an electric dipole source. Then, the directional enhancement of radiation is explored from Yagi-Uda geometry systems made of nanoparticles with optimal permittivities for reflector and directors.