Three-Dimensional Chiral MetaCrystals

TL;DR

This paper introduces a novel 3D chiral MetaCrystal that enables precise tuning of chiroptical properties through diffractive coupling, advancing nanoscale biosensing and nanophotonics applications.

Contribution

It proposes a new concept of 3D chiral MetaCrystal with tunable chiroptical properties via in-plane and out-of-plane diffractive coupling, addressing fundamental diffraction mechanisms.

Findings

Chiral dipolar modes can be excited along helix arms.

Far field optical resonances with in-plane side lobes are generated.

The MetaCrystal's properties are tunable across a broad spectral range.

Abstract

Fine control of the chiral light-matter interaction at the nanoscale, by exploiting designed metamaterial architecture, represents a cutting-edge craft in the field of biosensing, quantum and classic nanophotonics. Recently, artificially engineered 3D nanohelices have demonstrated programmable wide chiroptical properties by tuning materials and architecture, but fundamental diffractive aspects that are to the origin of chiral resonances still remain elusive. Here, we proposed a novel concept of three-dimensional chiral MetaCrystal, where the chiroptical properties are finely tuned by in-plane and out-of-plane diffractive coupling. Different chiral dipolar modes can be excited along the helix arms, generating far field optical resonances and radiation pattern with in-plane side lobes and suggesting that a combination of efficient dipole excitation and diffractive coupling matching controls the collective oscillations among the neighbor helices in the chiral MetaCrystal. This concept enables the tailorability of chiral properties in a broad spectral range for a plethora of forefront applications, since the proposed compact chiral MetaCrystal can be suitable for integration with quantum emitters and can open perspectives in novel schemes of enantiomeric detection.