skip to main content

SciTech ConnectSciTech Connect

Title: Optically resonant magneto-electric cubic nanoantennas for ultra-directional light scattering

Cubic dielectric nanoparticles are promising candidates for futuristic low-loss, ultra-compact, nanophotonic applications owing to their larger optical coefficients, greater packing density, and relative ease of fabrication as compared to spherical nanoparticles; besides possessing negligible heating at nanoscale in contrast to their metallic counterparts. Here, we present the first theoretical demonstration of azimuthally symmetric, ultra-directional Kerker's-type scattering of simple dielectric nanocubes in visible and near-infrared regions via simultaneous excitation and interference of optically induced electric- and magnetic-resonances up to quadrupolar modes. Unidirectional forward-scattering by individual nanocubes is observed at the first generalized-Kerker's condition for backward-scattering suppression, having equal electric- and magnetic-dipolar responses. Both directionality and magnitude of these unidirectional-scattering patterns get enhanced where matching electric- and magnetic-quadrupolar responses spectrally overlap. While preserving azimuthal-symmetry and backscattering suppression, a nanocube homodimer provides further directionality improvement for increasing interparticle gap, but with reduced main-lobe magnitude due to emergence of side-scattering lobes from diffraction-grating effect. We thoroughly investigate the influence of interparticle gap on scattering patterns and propose optimal range of gap for minimizing side-scattering lobes. Besides suppressing undesired side-lobes, significant enhancement in scattering magnitude and directionality is attained with increasing number of nanocubes forming a linear chain. Optimal directionality, i.e., the narrowest main-scattering lobe,more » is found at the wavelength of interfering quadrupolar resonances; whereas the largest main-lobe magnitude is observed at the wavelength satisfying the first Kerker's condition. These unique optical properties of dielectric nanocubes thus can revolutionize their applications at visible and near-infrared regions in the fields of nanoantennas, nanolasers, photovoltaics, and even in biomedicine.« less
Authors:
;  [1] ;  [2] ;  [3]
  1. Advanced Computing and Simulation Laboratory (A chi L), Department of Electrical and Computer Systems Engineering, Monash University, Clayton 3800, Victoria (Australia)
  2. Department of Chemical Engineering, Faculty of Engineering, Monash University, Clayton 3800, Victoria (Australia)
  3. (Australia)
Publication Date:
OSTI Identifier:
22413147
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 117; Journal Issue: 8; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; BACKSCATTERING; COMPARATIVE EVALUATIONS; DIELECTRIC MATERIALS; DIFFRACTION GRATINGS; EXCITATION; FABRICATION; HEATING; INTERFERENCE; LIGHT SCATTERING; MAGNETIC RESONANCE; NANOPARTICLES; NANOSTRUCTURES; OPTICAL PROPERTIES; PHOTOVOLTAIC EFFECT