Concealing arbitrary objects remotely with multi-folded transformation optics

This is the authors' abstract. We don't add key points for this paper.

An invisibility cloak that can hide an arbitrary object external to the cloak itself has not been devised before. In this Letter, we introduce a novel way to design a remote cloaking device that makes any object located at a certain distance invisible. This is accomplished using multi-folded transformation optics to remotely generate a hidden region around the object that no field can penetrate and that does not disturb the far-field scattering electromagnetic field. As a result, any object in the hidden region can stay in position or move freely within that region and remain invisible. Our idea is further extended in order to design a remote illusion optics that can transform any arbitrary object into another one. Unlike other cloaking methods, this method would require no knowledge of the details of the object itself. The proposed multi-folded transformation optics will be crucial in the design of remote devices in a variety of contexts. A remote cloaking device that does not require any knowledge of the properties of a target object has been designed by scientists in China. The cloak, theoretically investigated by Hongshen Chen and co-workers from Zhejiang University, creates a remote region that electromagnetic waves cannot penetrate, thus rendering any object in the region effectively invisible. The team used full-wave finite-element simulations to investigate the behaviour of the cloak. Provided the target object fits within the hidden region, the effectiveness of the cloak does not depend on the shape, composition or motion of the object. However, operation is limited to a narrow frequency band of electromagnetic waves. The researchers extended the idea by designing remote illusion optics that can make an arbitrary object appear like another object.