Broadband cloaking using 3D nano-assembled plasmonic meta-structures*

Broadband cloaking can be achieved via scattering suppression in the visible (VIS) and near infra-red (NIR) regions of the electromagnetic spectrum. Scattering suppression is possible by leveraging the plasmonic properties of the metallic nanoparticles (NPs). We have developed a model¹ to calculate the efficiency of scattered light when a spherical homogenous bare core is covered by a shell comprising a randomly-ordered collection of metallic NPs. Multiple scattering theory of Foldy and Lax was applied to calculate the interaction of light with the metallic NPs, in combination with the method of fundamental solutions. Numerical results demonstrated significant scattering suppression of up to 50% from the core-shell composite over a broad visible spectral range (400 nm-600 nm). The core sizes for the numerical experiments were varied between 400 nm to 900 nm along with an appropriate combination of NP sizes and NP filling fractions in the shell.