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Nanoantennas Can Change Phase of Light

The scientists now believe that they have found a path that could enable more powerful microscopes, telecommunications and computers. Specifically, the discovery is expected to have effects on technologies for "steering and shaping laser beams for military and communications applications, nanocircuits for computers that use light to process information, and new types of powerful lenses for microscopes."

The research builds on a previous modification how scientists have described how light reflects and refracts or bends while passing from one material into another, which is referred to as Snell's law. Each material has its own refraction index and all natural materials show positive refraction indexes. However, Purdue's nanoantennas can change the refraction and even achieve negative angles.

"Importantly, such dramatic deviation from the conventional Snell's law governing reflection and refraction occurs when light passes through structures that are actually much thinner than the width of the light's wavelengths, which is not possible using natural materials," said Vladimir Shalaev, scientific director of nanophotonics at Purdue's Birck Nanotechnology Center. "Also, not only the bending effect, refraction, but also the reflection of light can be dramatically modified by the antenna arrays on the interface, as the experiments showed."

According to the scientists, the nanoantennas feature V-shaped structures that are made of gold and are placed on top of a silicon layer. The antennas are 40 nm wide. Shalaev said that they are able to transmit light through an ultrathin "plasmonic nanoantenna layer" that is about 50 times smaller than the wavelength of light it is transmitting. "This ultrathin layer of plasmonic nanoantennas makes the phase of light change strongly and abruptly, causing light to change its propagation direction, as required by the momentum conservation for light passing through the interface between materials," Shalaev said.

  • Esto si es muy impresionante...sera la nueva era?
    Reply
  • jackbling
    Love to see a law broken; I like to think it stimulates the imagination of researchers in the relevant field, it has to be invigorating to have that barrier lifted.

    Even tho in this case it would appear they just amended the law.
    Reply
  • rawful
    What is a negative angle?
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  • doomgaze3
    How soon until I can buy an invisibility cloak?
    Reply
  • Haserath
    rawfulWhat is a negative angle?An angle greater than the angle of refraction, I would assume.

    Refraction is based on the speed of light through a medium.
    Reply
  • jgutz2006
    jackblingLove to see a law broken; Theft included? :-)
    Reply
  • sseyler
    jackblingLove to see a law broken; I like to think it stimulates the imagination of researchers in the relevant field, it has to be invigorating to have that barrier lifted.Even tho in this case it would appear they just amended the law.jackblingLove to see a law broken; I like to think it stimulates the imagination of researchers in the relevant field, it has to be invigorating to have that barrier lifted.Even tho in this case it would appear they just amended the law.
    Snell's law was never "broken". Snell's law is based on classical models of the behavior of light at interfaces. Saying "Snell's law was broken (by Purdue researchers)" is a statement that shows a profound misunderstanding of physics being talked about. I'm not blaming people for misunderstanding, because much of the fault of scientific ignorance and confusing is a consequence of poor reporting and communication. Albeit things like this point to a gross lack of scientific literacy among the general public.
    Reply
  • kronos_cornelius
    I am totally ignorant about this. But sounds interesting. Can Mr. Perry extend the article to review what Snell's law is, why sseyler thinks no law was broken, and what he means by a negative angle ?

    I'll come back to this article later to check.. meanwhile I'll check if TR and Wired for more info on this.
    Reply
  • @kronos_cornelius
    Negative refraction index:
    http://www.rikenresearch.riken.jp/images/figures/hi_3837.jpg
    Reply
  • freggo
    frozonichttp://d37nnnqwv9amwr.cloudfront.n 751942.pngthats all we need to do
    Well, NASA is actually using that on a few probes out there !
    Reply