2019/01/26 by Mohamed Ismail Abdelrahman, Hassan Saleh, Ivan Fernandez-Corbaton +5
Engineering · Materials Science · Mathematics · Physics and Astronomy · #Advanced Antenna and Metasurface Technologies #Broadband #Computational physics #Electromagnetic Scattering and Analysis #Geometry #Mathematics #Metamaterials and Metasurfaces Applications #Multipole expansion #Optics #Physics #Quantum mechanics #SPHERES #Scattering #Symmetry (geometry) #physics.class-ph #physics.optics
paper · pdf · doi:10.1063/1.5080980
published as APL Photonics 4.2 (2019): 020802 · 14 pages, 6 figures
openalex created_date 2019/01/11 · arxiv created 2019/01/26 · openalex publication_date 2019/02/01 · arxiv updated 2019/02/12 · openalex updated_date 2026/08/05
Manipulating the excitation of resonant electric and magnetic multipole moments in structured dielectric media has unlocked many sophisticated electromagnetic functionalities. This invited article demonstrates the experimental realization of a broadband Huygens’ source. This Huygens’ source consists of a spherical particle that exhibits a well-defined forward-scattering pattern across more than an octave-spanning spectral band at GHz frequencies, where the scattering in the entire backward hemisphere is suppressed. Two different low-index nonmagnetic spheres are studied that differ in their permittivity. This causes them to offer a different shape for the forward-scattering pattern. The theoretical understanding of this broadband feature is based on the approximate equality of the resonant electric and magnetic multipole moments in both amplitude and phase in low permittivity spheres. This is a key condition to approximate the electromagnetic duality symmetry which, together with the spherical symmetry, suppresses the backscattering. With such a configuration, broadband Huygens’ sources can be designed even if magnetic materials are unavailable. This article provides guidelines for designing broadband Huygens’ sources using low-index spheres that could be valuable to a plethora of applications.