Multipole optimization of light focusing by silicon nanosphere structures

authored by

N. Ustimenko, K. V. Baryshnikova, Roman Melnikov, D. Kornovan, Vladimir Ulyantsev, Boris N. Chichkov, Andrey B. Evlyukhin

Abstract

We investigate theoretically and numerically the light focusing by finite-size silicon nanostructures. The structural element is a sphere supporting dipole and quadrupole resonances of both electric and magnetic types. Our analytical model is based on the coupled multipole model (CMM) when the optical response of every particle in the structure is associated with the excitation of its multipole moments generating the secondary (scattered) waves in the system. Since the focusing effect is reached due to the interference between the incident and scattered waves, it is possible to control and optimize its efficiency by managing the spatial positions of particles. In this work, we study the applicability of the CMM and zero-order Born approximation (ZBA) for the electromagnetic field simulation in finite-size many-particle systems at the single-particle multipole resonances. The CMM and ZBA are verified by comparison of approximated results with the results obtained from the T-matrix method. We discuss the application of the developed approach for focusing structures composed of nanospheres arranged in rings and multi-objective optimization of their focal length and focal intensity via an evolutionary algorithm. We demonstrate the strong optimization potential of our calculation scheme, based on the ZBA, for designing effective ultra-thin metalenses.

Organisation(s)

Institute of Quantum Optics
PhoenixD: Photonics, Optics, and Engineering - Innovation Across Disciplines

External Organisation(s)

Lebedev Physical Institute of the Russian Academy of Sciences (LPI RAS)
St. Petersburg National Research University of Information Technologies, Mechanics and Optics (ITMO)

Type

Article

Journal

Journal of the Optical Society of America B: Optical Physics

Volume

38

Pages

3009-3019

No. of pages

11

ISSN

0740-3224

Publication date

10.2021

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

Atomic and Molecular Physics, and Optics, Statistical and Nonlinear Physics

Electronic version(s)

https://arxiv.org/abs/2103.01482 (Access: Open)
https://doi.org/10.1364/JOSAB.436139 (Access: Closed)