Superbackscattering nanoparticle dimers

Abstract

The theory and design of superbackscattering nanoparticle dimers are presented. We analytically derive the optimal configurations and the upper bound of their backscattering cross-sections. In particular, it is demonstrated that electrically small nanoparticle dimers can enhance the backscattering by a factor of 6.25 with respect to single dipolar particles. We demonstrate that optimal designs approaching this theoretical limit can be found by using a simple circuit model. The study of practical implementations based on plasmonic and high-permittivity particles reveal that fourfold enhancement factors might be attainable even with realistic losses.

Superbackscattering from single dielectric particles

“…It is also worth comparing its performance against other approaches towards achieving super-backscattering. Specifically, the 3.15 peak value obtained with moderate losses in figure 5 is in fact larger than the 3.05 value obtained with an optimal dimer of Te particles and the same amount of loss [8]. Therefore, our analysis reveals the peak backscattering values obtained with the presented particle outperform those of the optimal dimer, with the same material properties.…”

“…Under this perspective, the design of superbackscattering particles can be carried out by using superdirective and beamforming techniques studied in classic antenna theory [5,6]. Following this philosophy, the authors have studied the superbackscattering responses of antenna arrays [7] and nanoparticle dimers [8]. In this work we investigate a different route towards superbackscattering, based on the simultaneous, coherent excitation of different multipoles in dielectric resonators.…”

Nonradiating and radiating modes excited by quantum emitters in open epsilon-near-zero cavities

“…S6, and Liberal et al . ( 71 ) for the circuit model analysis of the light scattering of two coupled nanoparticles].…”

Mixtures of Multipoles—Should They Be in Your EM Toolbox?

“…In contrast, one aspect of the physics/optics interest in multipolar fields is that a single highly subwavelength element could conceptually produce needle-like radiated field performance. While the remainder of this article will emphasize forward-directed unidirectional concepts and example systems, superbackscattering responses of dielectric single [135] particles and dimers [163] via their electric and magnetic dipole and quadrupolar responses, as well as of arrays with specially engineered antennas [164], [165] have been demonstrated.…”