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European researchers have taken the world a step closer to fictional wizard Harry Potter's invisibility cape after they made an object disappear using a three-dimensional "cloak," a study published Thursday in the US-based journal Science showed.
Scientists from Karlsruhe Institute of Technology in Germany and Imperial College London used the cloak, made using photonic crystals with a structure resembling piles of wood, to conceal a small bump on a gold surface, they wrote in Science.
"It's kind of like hiding a small object underneath a carpet -- except this time the carpet also disappears," they said.
"We put an object under a microscopic structure, a little like a reflective carpet," said Nicholas Stenger, one of the researchers who worked on the project.
"When we looked at it through a lens and did spectroscopy, no matter what angle we looked at the object from, we saw nothing. The bump became invisible," said Stenger.
Invisibility cloaks have already been developed but they only worked on two dimensions. In other words, the objects that were supposed to be made invisible were immediately visible from the third dimension, the study said.
The "cloak" invented by the European team is the first to work on three dimensions.
It is composed of special lenses that bend light waves to suppress light as it scattered from the tiny bump the researchers were trying to make disappear, the study says.
The invisibility cloak and the bump were both minute. The cloak measured 100 microns by 30 microns -- one micron being one-thousandth of a millimeter -- and the bump it hid was 10 times smaller, said Stenger.
The researchers are working now to recreate the disappearing bump on a larger scale, but Stenger said Harry Potter's invisibility cloak would not be hanging in would-be wizards' wardrobes in the immediate future.
"Theoretically, it would be possible to do this on a large scale but technically, it's totally impossible with the knowledge we have now," he said.
"But it could become a reality in 10 years," he said, stressing, however, that the first invisibility cloak wouldn't be a flowing cape but a rigid structure.
The US military has ploughed money into several research groups working on invisibility technology, and scientists are probing other applications for the light-based processes, Stenger said.
"Light is already used in fiber optics, in telecommunications. And in the near future, we're going to use light more and more in computers," said Stenger.
