Multi-angle forward scattering of all-dielectric coded nanoparticles

Abstract

Metal-based nanoparticles are limited in their applications due to their inherent loss. Here, we propose all dielectric nanoparticles to enhance forward scattering efficiency. Firstly, all dielectric nanoparticles composed of lossless nanodisks are created. By changing the geometric size of the nanoparticles, 2π phase coverage can be achieved. We further coded these all-dielectric nanoparticles to construct nanoparticle coded metasurface. Then, we propose a superposition principle of super-grating coding sequence, which can control the scattering angle of coding metasurface. It is clear that theoretical results were compared with results of computer simulation. Due to the limitation of the generalized Snell’s law, the forward scattering angle of the encoded nanoparticle sequence is limited to several directions. In order to obtain the multi-angle forward scattering, we introduce the addition principle of coded nanoparticle sequences. By adding and subtracting two sequences of encoded nanoparticles, a new sequence of encoded nanoparticles was obtained. Furthermore, we introduce the complex phase encoding of the coded nanoparticles sequence to construct a new multi-functional and multi-angle coded nanoparticles sequence. Based on the principle of addition of complex phase-coded sequences of nanoparticles, the continuous angle scattering and superposition of scattering beams in any direction can be expected to be obtained.