If the incident radiation is p-polarized, however, the spectral response of the scattering cross section seems to be totally dissimilar 14. Different schemes have been proposed with plasmonic compounds, using a dipole moment of opposite phase to attain a scattering cancellation 11, 12, 13. In that case, the local polarizability of a nanowire with moderately wide diameter and the graphene coating sheet with the opposite signs can be mutually cancelled under suitable layout. Drastically reduced overall visibility of the scattering object that was conducted via graphene monolayer wrapping the cylinder, for the first time, was extended to the far-infrared range of frequencies by Chen and Alu 10. High conductivity within atomically thin layer of graphene, and significant tuning ability via the applied bias voltage, enables the cancellation of scattering effects. Graphene represents a groundbreaking and exciting material that combines suitable characteristics for the use in optoelectronic devices in far-infrared and THz region of frequencies due to the intrinsic ability to mold the surface current with low-loss rates 8, 9. Of course, light interacts with the nanoparticles, but the destructive interference at the different elements that constitute the complex nanostructure practically cancels out the scattered radiation. However, coatings can be designed such as metal-dielectric multilayer or metasurfaces to drastically reduce the scattered signal from subwavelength particles and make the assembly nearly undetectable 4, 5, 6, 7. The materials needed for practical applications of these techniques, either artificial or natural, require extremal values of their permittivity and/or permeability. In fact, a remote observer will not be able to detect the presence of the objects that are shielded and protected by optical cloaking. It means that an object located inside such a space region will practically stop interacting with the illuminating light 1, 2, 3.

In particular, by using various techniques based on transformation optics, the possibilities have appeared to electromagnetically isolate a space region for certain frequencies or range of frequencies. Photos and graphics subject to third party copyright used with permission or © Imperial College London.Recent progress in design and manufacturing of new photonic materials has enabled novel models and multifunctional devices to achieve unprecedented control of light. 'One of the most exciting applications is an electromagnetic cloak that could bend light around itself, similar to the flow of water around a stone, making invisible both the cloak and an object hidden inside,' said Professor Vladminr Shalaev, lead researcher who published his work in Science.The experiments are a development of work by Sir John Pendry at the Imperial College, London, who originally outlined how metamaterials could be constructed to cloak objects by deflecting and cloaking objects.Īrticle text (excluding photos or graphics) available under an Attribution-NonCommercial-ShareAlike Creative Commons license. Researchers at Purdue University in Indiana are using new ultra small 'nanotechnology' and 'metamaterials' combined with the mathematical principles of Einstein. An invisibility cloak, like the one Harry Potter used to wander around Hogwarts unseen, may be a reality within five years, claim scientists.

Invisible cloak project