Silicon nanostructure cloak operating at optical frequencies

TL;DR

This paper demonstrates a silicon-based optical cloak operating at 1550 nm that conceals surface deformations by manipulating light with nanostructured silicon, advancing invisibility technology.

Contribution

It introduces a practical, silicon nanostructure cloak functioning at optical frequencies, utilizing transformation optics for precise control of light.

Findings

Cloak operates at near-infrared wavelength of 1550 nm

Cloaks a 1.6 um2 region on a flat surface

Uses nanometre-scale silicon structures with spatially varying densities

Abstract

The ability to render objects invisible using a cloak - not detectable by an external observer - for concealing objects has been a tantalizing goal1-6. Here, we demonstrate a cloak operating in the near infrared at a wavelength of 1550 nm. The cloak conceals a deformation on a flat reflecting surface, under which an object can be hidden. The device has an area of 225 um2 and hides a region of 1.6 um2. It is composed of nanometre size silicon structures with spatially varying densities across the cloak. The density variation is defined using transformation optics to define the effective index distribution of the cloak.