Cloak of invisibility is finally within sight
From Grimms' fairytales to 'Harry Potter', the cloak of invisibility has played a major role in fiction. Now scientists have taken a small but important new step towards making it a reality.
Researchers at Germany's Karlsruhe Institute of Technology report that they were able to cloak a tiny bump in a layer of gold, preventing its detection at nearly visible infrared frequencies.
Their cloaking device also worked in three dimensions, while previously developed cloaks worked in two, lead researcher Tolga Ergin said.
The cloak is a structure of crystals with air spaces in between, sort of like a woodpile, which bends light, hiding the bump in the gold layer beneath, the researchers reported in online journal 'Science'.
In this case, the bump was so tiny that a magnifying lens was needed to see it. But Mr Ergin said: "In principle, the cloak design is completely scalable; there is no limit to it."