Invisibility cloak one step closer with light-bending material

by Rich Bowden - Aug 10 2008, 20:22

The concept of a Harry Potter-style cloaking mechanism has been brought one tantalising step closer as U.S. scientists unveil new material which can bend visible light the wrong way around objects.

Scientists at the University of California will publish work in the journals Science and Nature later this week which will describe a new metamaterial which has the ability to bend light around a object. Effectively observers would see light from behind the object screened by the cloak rendering them invisible.

Though such an "invisibility cloak" for anything from people to tanks and ships is still many years away, the research has brought closer the idea that bending light around an object will conceal it. The work follows on from previous research which used microwaves for the same effect.

Xiang Zhang, the leader of the researchers, said: “In the case of invisibility cloaks or shields, the material would need to curve light waves completely around the object like a river flowing around a rock.” An observer looking at the cloaked object would then see light from behind it – making it seem to disappear, the Sunday Times reported.

Metamaterials are artificially engineered structures that have "extraordinary optical properties that do not exist in nature," the researchers write in Science. "They can alter the propagation of electromagnetic waves, resulting in negative refraction, subwavelength imaging and cloaking."

The team were able to construct a multilayered structure which "unambiguously exhibits negative refractive index," LiveScience reports the statement in Nature. "This straightforward and elegant demonstration enhances our ability to mould and harness light at will."

The technology has enormous implications in areas such as stealth weaponry hence its enthusiastic backing from the military.

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