Electrically Reconfigurable Optical Metamaterial Based on Colloidal Dispersion of Metal Nano-Rods in Dielectric Fluid

TL;DR

This paper presents an electrically reconfigurable optical metamaterial made of colloidal metal nanorods in a dielectric fluid, enabling dynamic control of optical properties like refractive index and birefringence.

Contribution

It introduces a novel method to dynamically control optical metamaterials using dielectrophoretic manipulation of nanorods in a fluid.

Findings

Nanorods can be precisely positioned and oriented with electric fields.

Optical properties such as refractive index and birefringence are tunable.

Object visibility can be reduced using the metamaterial.

Abstract

Optical metamaterials capture the imagination with breathtaking promises of nanoscale resolution in imaging and invisibility cloaking. We demonstrate an approach to construct a metamaterial in which metallic nanorods, of dimension much smaller than the wavelength of light, are suspended in a fluid and placed in a nonuniform electric field. The field controls the spatial distribution and orientation of nanorods because of the dielectrophoretic effect. The field-controlled placement of nanorods causes optical effects such as varying refractive index, optical anisotropy (birefringence), and reduced visibility of an object enclosed by the metamaterial.