Directional visible light scattering by silicon nanoparticles

Abstract

Directional light scattering by spherical silicon nanoparticles in the visible spectral range is experimentally demonstrated for the first time. These unique optical properties arise because of simultaneous excitation and mutual interference of magnetic and electric dipole resonances inside a single nanosphere. Such behaviour is similar to Kerker's-type scattering by hypothetic magneto-dielectric particles predicted theoretically three decades ago. Here we show that directivity of the far-field radiation pattern of single silicon spheres can be strongly dependent on the light wavelength and the nanoparticle size. For nanoparticles with sizes ranging from 100 to 200 nm, forward-to-backward scattering ratio above six can be experimentally obtained, making them similar to 'Huygens' sources. Unique optical properties of silicon nanoparticles make them promising for design of novel low-loss visible-and telecom-range metamaterials and nanoantenna devices.

Laser printing of silicon nanoparticles with resonant optical electric and magnetic responses

“…This effect is realized when e 0 a m ¼ a p , where a m and a p are the magnetic and electric dipole polarizabilities of the nanoparticle. Directional light scattering by spherical silicon nanoparticles in the visible spectral range has been recently experimentally demonstrated 42,43 . This effect can be used for efficient light coupling into silicon waveguides.…”

Suppression of scattering for small dielectric particles: anapole mode and invisibility

“…Minimization of differential scattering functions [34][35][36][37] does not minimize the total scattering. For example, minimization of the forward scattering due to the second Kerker conditions 34 is quite close to local minimum in the scattering (see Fig.…”

Monodisperse silicon nanocavities and photonic crystals with magnetic response in the optical region

“…Theoretical results on full dielectric optical antennas 28,29 , magnetic type optical trapping 25 and metamaterials-related devices 22,23 have been published. Very recently, it has been reported about the directional scattering properties of high refractive index nanoparticles produced by simultaneous excitation and mutual interference of magnetic and electric dipole resonances inside a single high refractive index particle [33][34][35] , which is a strong evidence of the magnetic response of silicon colloids at optical frequencies. Owing to the welldefined optical resonant modes, high refractive index colloids, whose size is much smaller than the wavelength of light, behave as photonic nanocavities.…”

“…Owing to the welldefined optical resonant modes, high refractive index colloids, whose size is much smaller than the wavelength of light, behave as photonic nanocavities. So far, the fabrication of high refractive index particles concerned on different approaches as lithography 34 , chemical vapour deposition 26 and laser ablation 30,31,33 methods. However, the processing of monodisperse high refractive index nanoparticles is still a challenge, which limits the usage of high refractive index particles to true nano-optics applications.…”