Beyond Kerker's conditions: simultaneously nearly zero forward and nearly zero backward scatterings

TL;DR

This paper demonstrates that sub-wavelength passive scatterers can be engineered to exhibit both nearly zero forward and backward scattering simultaneously by exploiting interference of dipolar quadrupole modes, advancing control over light scattering.

Contribution

It introduces a novel approach to achieve simultaneous nearly zero forward and backward scattering using interference of dipolar quadrupole modes, extending beyond traditional Kerker's conditions.

Findings

Passive nano-structures can exhibit both NZFS and NZBF.

Interference of dipolar quadrupole modes enables simultaneous zero scattering directions.

Proposed multi-layered materials for experimental realization at optical frequencies.

Abstract

With theoretical analyses and numerical calculations, we show that a passive scatterer at the sub-wavelength scale can simultaneously exhibit both nearly zero forward scattering (NZFS) and nearly zero backward scattering (NZBF). It is related to the interference of dipolar quadrupole modes of different origin, leading to coexistence of Kerker's first and second conditions at the same time. For optical frequencies, we propose two different sets of composited materials in multi-layered nano-structures, i.e., CdTe/Si/TiO2 and TiO2/Au/Si, for the experimental realization.