Fabrication and characterization of three-dimensional biomimetic chiral composites

Mark D Turner,Gerd E Schröder-Turk,Min Gu

doi:10.1364/oe.19.010001

Mark D Turner, Gerd E Schröder-Turk + Show 1 more

Open Access

https://doi.org/10.1364/oe.19.010001

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Abstract

Here we show the fabrication and characterization of a novel class of biomimetic photonic chiral composites inspired by a recent finding in butterfly wing-scales. These three-dimensional networks have cubic symmetry, are fully interconnected, have robust mechanical strength and possess chirality which can be controlled through the composition of multiple chiral networks, providing an excellent platform for developing novel chiral materials. Using direct laser writing we have fabricated different types of chiral composites that can be engineered to form novel photonic devices. We experimentally show strong circular dichroism and compare with numerical simulations to illustrate the high quality of these three-dimensional photonic structures.

Highlights

Nature‟s ability to self-assemble complex nanostructured materials with superior properties to that of conventional materials, has interested scientists across a range of disciplines [1,2,3,4,5]
Chiral geometries were first introduced to photonic crystals (PCs) with the demonstration that the spiral PC was as a three-dimensional (3D) PC with large complete photonic bandgaps [16]
It was discovered that these spiral-based chiral PCs show strong circular dichroism [11,12] manifesting in the existence of polarization stop bands [17]

Summary

Introduction

Nature‟s ability to self-assemble complex nanostructured materials with superior properties to that of conventional materials, has interested scientists across a range of disciplines [1,2,3,4,5]. The design of chiral asymmetries within nanophotonics has emerged due to the strong discrimination of circular polarization in light-matter interactions This unique ability has led to the development of applications such as nanoscale plasmonic motors [6] and ultrasensitive spectroscopy of chiral biomolecules [7]. It was discovered that these spiral-based chiral PCs show strong circular dichroism [11,12] manifesting in the existence of polarization stop bands [17] These chiral nanophotonic designs typically have only uniaxial chirality and are highly anisotropic, greatly limiting their potential applications. We demonstrate the fabrication and characterisation of a novel class of 3D photonic microstructures inspired by a recent finding in butterfly wing-scales [18,19,20] These biomimetic photonic chiral composites have cubic symmetry, are fully interconnected, have robust mechanical strength and possess chirality. We propose the engineering of multiple chiral composites in a single structure to form photonic devices with possible applications such as circularly polarized beam splitters and super prisms

The single srs network

Photonic chiral composites

Numerical characterization

Experimental setup

Findings

Conclusion