Tapering Waveguide Captures a Rainbow

SubComdTaco passes along news of researchers in the US who have trapped a rainbow in a tapering waveguide. The research is described (PDF) on the arXiv. "In 2007, Ortwin Hess of the University of Surrey in Guildford, UK, and colleagues proposed a technique to trap light inside a tapering waveguide [made of metamaterials]... The idea is that as the waveguide tapers, the components of the light are made to stop in turn at ever narrower points. That's because any given component of the light cannot pass through an opening that's smaller than its wavelength. This leads to a 'trapped rainbow.' ... Now Vera Smolyaninova of Towson University in Baltimore, Maryland, and colleagues have used a convex lens to create the tapered waveguide and trap a rainbow of light. They coated one side of a 4.5-mm-diameter lens with a gold film..., and laid the lens — gold-side down — on a flat glass slide which was also coated with film of gold. Viewed side-on, the space between the curved lens and the flat slide was a layer of air that narrowed to zero thickness where the lens touched the slide — essentially a tapered waveguide. When they shone a multi-wavelength laser beam at the... gilded waveguide, a trapped rainbow formed inside. This could be seen as a series of colored rings when the lens was viewed from above with a microscope: the visible light leaked through the thin gold film."

Leprechaun

[daveime]

So the bloody leprechaun lied to us !

You need to have two very thin pots of gold first, so you can find the end of the rainbow.

skittles

[Lehk228]

did they try tasting it?

What they're really researching

[Broofa]

Dr. Hess was later quoted as saying, "While we're obviously pleased with our success so far, we won't be satisfied until we've trapped not only the rainbow, but the leprechaun and pot of gold as well. Until then, we remain disturbingly dependent on grant money for our research."

Leprechaunic

[ShakaUVM]

>>You need to have two very thin pots of gold first, so you can find the end of the rainbow.

I wonder if you kidnap the scientists they'll grant you three wishes?

Tag: Leprechaun

Re:Also neat because?

[Anonymous Coward]

Rainbow coloured porn that's trapped in meta-materials, of course.

Re:Leprechaunic

[dangitman]

I wonder if you kidnap the scientists they'll grant you three wishes?

Yes, unless one of the wishes is to know how your cat is doing.

Re:Also neat because?

[daveime]

Black holes have been trapping light since the Big Bang (or "shortly afterwards" anyway, in cosmic terms).

I think God has prior art on that one. Once man can also trap gravity, strong and weak electromagnetic forces and time, I'll concede to your assertion.

Re:Also neat because?

[Anonymous Coward]

Man has been trapping time every since Bejeweled was invented.