Duke University Creates Perfect, Centimeter-scale Invisibility Cloak

MrSeb writes "Scientists at Duke University have created the first invisibility cloak that perfectly hides centimeter-scale objects. While invisibility cloaks have been created before, they have all reflected some of the incident light, ruining the illusion. In this case, the incident light is perfectly channeled around the object, creating perfect invisibility. There are some caveats, of course. For now, the Duke invisibility cloak only works with microwave radiation — and perhaps more importantly, the cloak is unidirectional (it only provides invisibility from one very specific direction). The big news here, though, is that it is even possible to create an invisibility cloak of any description. It is now just a matter of time before visible-light, omnidirectional invisibility cloaks are created."

Comments

Hmmm

[ciderbrew]

I'll believe it when I see it.

Re:Hmmm

[vlm]

Unidirectional microwave-only cloak -> omnidirectional visible light cloak?
It's gonna take a little more than "a few years".

The biggest problem I see from having done lots of RF engineering in the lower microwave range (mostly FCC part 97, but some telco work, aside from the wifi stuff that "everyone" does) is specs always improve, but the basic layouts / schematics / ideas don't change very much.

Higher freqs? Sure. A heck of a lot of orders of magnitude? Um, maybe, over the course of a lifetime and billions of bucks. Unidirectional to omni? Um no.

You can make a "better" horn antenna. You can do crazy stuff to eat the sidelobes. You can make it lighter, or wider bandwidth, or better behavior when it multimodes. You can make it lower loss. But fundamentally, its still a microwave horn antenna. This fundamental issue is analogy to trying to make a unidirectional cloak.

This doesn't mean its useless. You know what would be funny? A anti-anything missile that is radar invisible from the pointy end. Who cares if you can see it from the back or side, its too late by then. To the best of my limited knowledge from playing Harpoon, etc, all American anti-anti-ship missiles are radar guided as are the ancient Phalanx miniguns.

One interesting RF observation is its a serious challenge to "really" do microwave RF work over a factor of 2 in freq. Can be done, but doesn't mean its easy or its more than cheating (multiple colocated systems... making a big pile simply isn't technologically interesting). The relevance is an X-band invisible car would probably not be invisible at K band. Or something invisible to red is probably going to be blue visible, unless you run multiple systems. Or something invisible to blue is probably not going to be invisible to IR targeting lasers.

Optimism.

[Anonymous Coward]

"It is now just a matter of time before visible-light, omnidirectional invisibility cloaks are created."

Wow. Just Wow. Just because we sent men to the moon, it does not mean that we'll be traveling to other galaxies soon.

Unless of course by "just a matter of time", they mean like a hundred thousand years.

Haven't they learned from Star Trek?

[Tastecicles]

Surely it's gotta have a tailpipe...