4 ms·

Scientists Invent New Way to Control Light

59 points by Libertatea 12y ago

beambot 12y ago
> A device resembling a plastic honeycomb yet infinitely smaller than a bee’s stinger ... "Infinitely smaller"....? That's horrible scientific reporting!
- DubiousPusher 12y ago
  It's literally infinitely smaller!
- spott 12y ago
  The article is horribly written...
TheSoftwareGuy 12y ago
can anybody explain why this is better than a mirror?
- leeoniya 12y ago
  i had exactly the same thought. why not a nanomirror?
- wtvanhest 12y ago
  Mirrors absorb and transmit light. This article from wiki explains what a perfect mirror would be: http://en.wikipedia.org/wiki/Perfect_mirror http://en.wikipedia.org/wiki/Perfect_mirror I believe the most important part of the article is: "The team then ran light beams through the lattices and confirmed that they could flow light (without loss) through turns that are twice as tight as any done previously." If you can bend light without loss, I imagine that is very valuable. All that said, IANAP (I am not a physicist) so if someone else can correct me or add more information, I'm sure that would be helpful.
  - spott 12y ago
    It can't bend light without loss... It actually is pretty lossy (the paper references an attenuation of 270 cm^-1, or 1/e loss per 270 cm.)
- vmarsy 12y ago
  "controlling the light beams without losing their energy has been the challenge" I guess perfect mirrors that don't loose any energy don't exist?
  - fargail 12y ago
    I like how you quoted the word that you misspelled on the second line
    - glibgil 12y ago
      What a nauseating comment.
- bcbrown 12y ago
  It's not useful to transmit light through air; instead waveguides are used[0]. I don't know all the benefits, but I imagine trying to keep a path through space for light beams to travel is harder than using a waveguide. In that case, mirrors are useless. You can think of a waveguide as being a highly engineered mirror, really. However, the turning radius of a fiber-optic beam isn't great, and apparently this is an improvement on that. http://en.wikipedia.org/wiki/Waveguide#Optical_waveguides http://en.wikipedia.org/wiki/Waveguide#Optical_waveguides
- spott 12y ago
  One reason is because mirrors (freespace optics in general), are limited in how narrowly confined the beam can be. Generally speaking, waveguides can have cross sectional area of ~ λ^2 or less, while freespace optics can only get below that for some small focus volume. So a chip with mirrors on it would have to be much much bigger to handle the beam width of all the laser light.
spott 12y ago
This article is horrible. The paper is here: http://www.opticsinfobase.org/oe/abstract.cfm?URI=oe-22-21-25788 http://www.opticsinfobase.org/oe/abstract.cfm?URI=oe-22-21-2... First off, the reason you want light for transmission on chips isn't because it is "faster", it is because it is less susceptible to electromagnetic interference. The speed of light in a medium is the speed electronic signals travel, and the speed light waves travel. However, electronic signals bleed interference, and light waves don't. You also can switch light waves on and off at theoretically higher rates, with less power, so optical signals can break the 4 GhZ barrier we are currently stuck at. Secondly, they can't bend light without loss. Just with less loss. But the interesting part of the paper is the fact that the turning is selective depending on polarization (one polarization turns, and one doesn't). They are also able to turn light very quickly, compared to the wavelength of the light. So the radius of curvature divided by the wavelength of the light is around 6.4 for this paper.

59 points by Libertatea 12y ago

> A device resembling a plastic honeycomb yet infinitely smaller than a bee’s stinger ... "Infinitely smaller"....? That's horrible scientific reporting!

DubiousPusher 12y ago
It's literally infinitely smaller!
spott 12y ago
The article is horribly written...

TheSoftwareGuy 12y ago

can anybody explain why this is better than a mirror?

leeoniya 12y ago
i had exactly the same thought. why not a nanomirror?
wtvanhest 12y ago
Mirrors absorb and transmit light. This article from wiki explains what a perfect mirror would be: http://en.wikipedia.org/wiki/Perfect_mirror http://en.wikipedia.org/wiki/Perfect_mirror I believe the most important part of the article is: "The team then ran light beams through the lattices and confirmed that they could flow light (without loss) through turns that are twice as tight as any done previously." If you can bend light without loss, I imagine that is very valuable. All that said, IANAP (I am not a physicist) so if someone else can correct me or add more information, I'm sure that would be helpful.
- spott 12y ago
  It can't bend light without loss... It actually is pretty lossy (the paper references an attenuation of 270 cm^-1, or 1/e loss per 270 cm.)
vmarsy 12y ago
"controlling the light beams without losing their energy has been the challenge" I guess perfect mirrors that don't loose any energy don't exist?
- fargail 12y ago
  I like how you quoted the word that you misspelled on the second line
  - glibgil 12y ago
    What a nauseating comment.
bcbrown 12y ago
It's not useful to transmit light through air; instead waveguides are used[0]. I don't know all the benefits, but I imagine trying to keep a path through space for light beams to travel is harder than using a waveguide. In that case, mirrors are useless. You can think of a waveguide as being a highly engineered mirror, really. However, the turning radius of a fiber-optic beam isn't great, and apparently this is an improvement on that. http://en.wikipedia.org/wiki/Waveguide#Optical_waveguides http://en.wikipedia.org/wiki/Waveguide#Optical_waveguides
spott 12y ago
One reason is because mirrors (freespace optics in general), are limited in how narrowly confined the beam can be. Generally speaking, waveguides can have cross sectional area of ~ λ^2 or less, while freespace optics can only get below that for some small focus volume. So a chip with mirrors on it would have to be much much bigger to handle the beam width of all the laser light.

spott 12y ago

This article is horrible. The paper is here: http://www.opticsinfobase.org/oe/abstract.cfm?URI=oe-22-21-25788 http://www.opticsinfobase.org/oe/abstract.cfm?URI=oe-22-21-2... First off, the reason you want light for transmission on chips isn't because it is "faster", it is because it is less susceptible to electromagnetic interference. The speed of light in a medium is the speed electronic signals travel, and the speed light waves travel. However, electronic signals bleed interference, and light waves don't. You also can switch light waves on and off at theoretically higher rates, with less power, so optical signals can break the 4 GhZ barrier we are currently stuck at. Secondly, they can't bend light without loss. Just with less loss. But the interesting part of the paper is the fact that the turning is selective depending on polarization (one polarization turns, and one doesn't). They are also able to turn light very quickly, compared to the wavelength of the light. So the radius of curvature divided by the wavelength of the light is around 6.4 for this paper.