Issue 43, 2020

Highly efficient unidirectional forward scattering induced by resonant interference in a metal–dielectric heterodimer

Abstract

We demonstrate that a metal–dielectric heterodimer structure can satisfy a nearly ideal first Kerker condition at a wavelength close to the resonance peak of the dimer, yielding efficient unidirectional forward scattering with a high forward-to-backward scattering ratio (≈48 dB) and remarkable enhancement of the forward scattering intensity (∼2.68 times compared to a single dielectric nanoparticle). Using a rigorous analytical dipole–dipole interaction model, the underlying mechanism is revealed, in which the originally weak electric dipole moment of the dimer is significantly enhanced owing to the strong resonant interference between the localized surface plasmon resonance of the metal and the Mie resonances of the dielectric material, which could up-match the magnetic dipole moment of the dimer at a wavelength close to the resonance peak, boosting the forward scattering efficiency. To achieve the optimal conditions, the sizes of the metal and dielectric constituents as well as the gap distance of the dimer have to be physically and delicately tuned to ensure a perfect match in both the amplitudes and phases of the electric and magnetic dipole moments of the dimer. On top of that, the loss of the heterodimer can be effectively suppressed to a level well below that of a pure metal nanoparticle, which further benefits the forward scattering efficiency. The flexibility in designing the dimer geometry and choosing metal–dielectric material combinations enables efficient unidirectional forward scattering in a broadband spectrum (UV to visible) with an intermediate gap distance (10–20 nm), greatly expanding the application scope. The proposed hybrid dimer could serve as a powerful and versatile building block in many emergent fields such as metasurfaces, nanoantennae, etc.

Graphical abstract: Highly efficient unidirectional forward scattering induced by resonant interference in a metal–dielectric heterodimer

Supplementary files

Article information

Article type
Paper
Submitted
30 Sep 2020
Accepted
22 Oct 2020
First published
23 Oct 2020

Nanoscale, 2020,12, 22289-22297

Highly efficient unidirectional forward scattering induced by resonant interference in a metal–dielectric heterodimer

S. Sun, D. Wang, Z. Feng and W. Tan, Nanoscale, 2020, 12, 22289 DOI: 10.1039/D0NR07010F

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements