Exterior optical cloaking and illusions by using active sources: a boundary element perspective

TL;DR

This paper demonstrates how active sources can be used to achieve optical cloaking and illusion effects, transforming the appearance of objects outside the device using boundary element methods.

Contribution

It introduces a boundary element approach to design active sources that create cloaking and illusion effects, including invisibility, for objects outside the devices.

Findings

Active sources can cloak objects outside the device.

Active sources can create illusion effects to make objects appear as different shapes.

Numerical simulations confirm the effectiveness of the proposed methods.

Abstract

Recently, it was demonstrated that active sources can be used to cloak any objects that lie outside the cloaking devices [Phys. Rev. Lett. \textbf{103}, 073901 (2009)]. Here, we propose that active sources can create illusion effects, so that an object outside the cloaking device can be made to look like another object. invisibility is a special case in which the concealed object is transformed to a volume of air. From a boundary element perspective, we show that active sources can create a nearly "silent" domain which can conceal any objects inside and at the same time make the whole system look like an illusion of our choice outside a virtual boundary. The boundary element method gives the fields and field gradients (which can be related to monopoles and dipoles) on continuous curves which define the boundary of the active devices. Both the cloaking and illusion effects are confirmed by numerical simulations.