Broadband optical magnetism in chiral metallic nanohole arrays by shadowing vapor deposition

TL;DR

This paper demonstrates broadband optical magnetism in chiral metallic nanohole arrays by multi-scaled 3D meta-elements, with experimental realization using shadowing vapor deposition, enabling potential applications in plasmonic sensing and energy concentration.

Contribution

It introduces a novel fabrication method for broadband optical magnetism in chiral nanohole arrays with experimental validation.

Findings

Achieved broadband optical magnetism in nanohole arrays.

Demonstrated large circular polarization-dependent transmission.

Validated the approach with experimental fabrication.

Abstract

We show that broadband optical magnetism can be achieved through incorporating multi-scaled 3D metallic meta-elements into Z-shaped nanohole arrays. The broadband effect arises from the excitation of multiple magnetic resonances in the meta-elements at different wavelengths. Moreover, the nanohole arrays exhibit a large transmission difference for left- and right-handed circularly polarized incident light due to the chiral arrangement of the meta-elements. More importantly, we have realized experimentally the broadband behavior for the optical range in Ag nanohole arrays fabricated by using a shadowing vapor deposition method. Our study opens up new opportunities for achieving broadband artificial magnetism at visible frequencies which allows possible applications in plasmonic bio-sensors or energy concentrators.