Last year, the world went bonkers when scientists at Duke University in North Carolina unveiled the world’s first invisibility cloak. There weren’t no let up in the wall-to-wall media coverage it generate. And impressive though it was, what many reporters forgot to mention was that the cloak works only for microwaves at a single frequency and only in two dimensions.
So if yer happen to be a sandwich flat alien with microwave radar dishes for eyes then this cloak mighta fooled ya.
Now Igor “Smelly knees” Smolyaninov and buddies at the University of Maryland in College Park, have built the world’s first invisibility cloak that works at optical frequencies. The cloak is based on a design by Vladimir Shalaev from Purdue University who dreamt up a new method building invisibility cloaks that gets around some of the limitations that otherwise prevent them working at optical frequencies.
And of course, there are a few catches this time too. This cloak also works only in two dimensions, when the light is polarised in a particular way and over a scale of only a few micrometers. But from acrons to oak trees grow.
So if yer happento be a sandwich flat alien the size of a grain of pollen wearing polaroid sun glasses, this is the invisibility cloak for you.
What’s amazing, though, is the speed with which these eggheads are a-buildin and a-developin this technology. It ain’t no more than a handful of years since people said that optical invisibility cloaks ain’t possible, even in theory. Even the optimists were sayin only last year that it’d be 10 to 15 years before we see optical versions. So hats off to the Smelly Knees of Smolyaninov.
Ref: arxiv.org/abs/0709.2862: Electromagnetic Cloaking in the Visible Frequency Range