Near-field polarization distribution of Si nanoparticles near substrate

Abstract

Abstract. Structure of the near-field intensity and polarization distributions, the latter is described with the generalized 3D Stokes parameters, of a spherical Si subwavelength nanoparticle in a nonmagnetic and non-absorbing media near a dielectric substrate has been studied in detail with the help of the Mie theory and an extension of the Weyl's method for the calculation of the reflection of dipole radiation by a flat surface. It is shown that for the nanoparticle near the substrate the interference effects due to the scattering by the nanoparticle and interaction with the substrate play an essential role. We also demonstrate how these effects depend on the dielectric properties of the nanoparticle, its size, distance to the substrate as well as on the polarization, wavelength and incident angle of the external light field.Control of the near-field in the proximity of nanostructures is a key to shaping the spatial intensity of light and its polarization distribution at the nanoscale [1]. Near-field being formed by the interference of the incident electromagnetic field with the local field of the nanoparticle strongly depends both on polarization of the incident field and properties of the nanoparticles (their shape and materials). The orientation of the near-field polarization is a key quantity in many theoretical studies on nanooptics, nanophotonic devices and optical sciences in general. Recently, we studied theoretically how the nearfield polarization distribution of a plasmonic prolate nanospheroid interacting with a plane electromagnetic wave depends on the polarization and frequency of the incident electromagnetic field [2,3].Аlong with plasmonic nanoparticles, the nanoparticles made of high refractive dielectric or semiconductor materials have recently received considerable attention in the nanophotonics for their ability to control and manipulate the light in the near-field [4,5]. They allow direct engineering a magnetic field response at optical frequencies in addition to the electric field response in plasmonic structures. As a fundamental building block, the dielectric spherical nanoparticle presents both strong magnetic dipole and electric dipolar responses corresponding to the basic Mie resonances. In many real applications the nanoparticles are often located near a substrate and the influence of the substrate may be

Quantum Optics in Nanostructures

“…The near-field polarization was also studied for a dielectric nanosphere with a high refractive index (Si) both in free space and on a quartz substrate [ 54 , 55 ]. In the case of a dielectric NP, regions of change in the polarization are most pronounced at wavelengths that correspond to electric and magnetic dipole and quadrupole resonances.…”