Contents 1 Introduction
Optical properties of silicon nanoparticles attract great scientific interest [1]–[3]. These subwavelength scatterers can support the excitation of multipolar resonances [4] which enhance the light-matter interaction in a controlable manner just by changing the nanoparticles size, geometry and material [5], [6]. It can be used for different applications, including nanoantennas [7], [8] and nanolenses [9], [10], cloaking [11], [12], chemiluminescence microdevices [7] and composite plasmonic waveguide sensors [13], [14]. Directional scattering induced by third order multipoles contribution in nanocylinders was recently investigated in [15]. A multipolar light-matter interaction has also been demonstrated by modifying properties of the illuminating radiation applied to a nano-scatterer with selective excitation of individual multipole modes in standing wave configurations [16]. Despite their intriguing properties and the theoretical progress in studying multipole resonances [5], their contribution to the scattering when they are excited in dielectrics of non-symmetrical shape is in fact omitted. To fulfill this gap in electromagnetic theory, we use finite element method in COMSOL Multiphysics and multipole decomposition technique [17] to study multipole resonances excited in silicon nanoparticles of conical geometries with varying height .
