Inverse design of compact optical cloaks and experimental demonstration at microwave frequencies

TL;DR

This paper demonstrates the inverse design and experimental realization of compact microwave optical cloaks using 3D printing, effectively reducing scattering and hiding objects of specific sizes and shapes.

Contribution

It introduces a novel inverse design method for optical cloaks at microwave frequencies and validates it through experimental demonstration with 3D printed structures.

Findings

Designs effectively reduce scattering of incident light.

Experimental results agree with numerical simulations.

Cloaks conceal objects up to the wavelength size.

Abstract

Inverse design in photonics has gathered increasing attention as a powerful approach that goes beyond the intuition-based designs. In this Letter, we present the inverse design and experimental demonstration of compact optical cloaks at microwave frequencies is conducted. Two different configurations of rectangular and circular cloaks are numerically designed to reduce the scatterings of incident light interacting with a perfect electrical conductor object. The designed cloaking structures consist of dielectric polylactide material with a low refractive index and they are fabricated by 3D printing approach. The experimental measurements are in good agreement with the numerical calculations. The designed region covering (4{\lambda} x 4{\lambda}) area enables hiding circular object of {\lambda} diameter where {\lambda} denotes the wavelength of incident light. The proposed approach may enable the concealment of different objects possessing various size and shapes.