The world’s first visible light invisibility cloak

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

4 Responses to “The world’s first visible light invisibility cloak”

  1. Bob says:

    Your English is appalling.

  2. GeorgeP says:

    Might there not be difficulties using a cloak for anything intelligent inside (sensors, humans, etc) as follows?

    Since the intent is to pass electromagnetic frequencies of interest around the contained object, then whatever’s inside the cloak won’t be able to see (or otherwise sense) anything!

    Check me on this please.

    Side thought: Just what would someone “see” inside a cloak?

  3. [...] gone crazy over metamaterials cos they can be used to build invisibility cloaks, as ya’ll saw just the other week. There’s usually some drawback the media coverage never tells ya which means that we [...]

  4. Iain Cochran says:

    What I am a-wundrin, is:

    Why O Why O Why are Earth Physicists refusing to investigate all the vast other ’spectra’ at other velocities and energies than light?

    This fixed idea is stopping us find out things like:

    Air-based Force fields – there is an eletronic/energy frequency at which air becomes remarkably solid and can be manipulated into such a thing as a ‘force field’.

    Gravitation – gravity ‘waves’ as such don’t exist, though these things that earthly scientists are trying to measure are actually distortions interfering with an existing energy field. If they started looking for the velocity and frequency of the gravitational attraction (and indeed repulsion) waves/energies they this might throw up something useful.

    Magnetism is of the same ilk as gravity, just that it has a slightly different velocity and
    is slow enough to cause excitement to those
    who are happy with the electromagnetic spectrum.

    Observation seems to have escaped the mathematical types and they are clouding observational science with their mathematical conveniences.

    This is bourne out of mans fixed idea about the EM spectrum being the only spectrum that exists to be observed.

    Not true. Look elsewhere, or, as a hint, elsewhen.

    Iain.