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'Optical Fiber' Made Out of Thin Air

Posted by Soulskill on from the sufficiently-advanced-technology dept.

Dave Knott writes: Scientists from the University of Maryland say they have turned thin air into an "optical fiber" that can transmit and amplify light signals without the need for any cables. As described in the research, this was accomplished by generating a laser with its light split into a ring of multiple beams forming a pipe. Very short and powerful pulses from the laser are used to heat the air molecules along the beam extremely quickly. Such rapid heating produces sound waves that take about a microsecond to converge to the center of the pipe, creating a high-density area surrounded by a low-density area left behind in the wake of the laser beams. The lower density region of air surrounding the center of the air waveguide has a lower refractive index, keeping the light focused, and allowing the higher-density region (with its correspondingly higher index of refraction) to act like an optical fiber. The findings, reported in the journal Optica, have applications in long range laser communications, high-resolution topographic mapping, air pollution and climate change research, and could also be used by the military to make laser weapons.

4 of 115 comments (clear)

  1. But... by camperdave · · Score: 3, Insightful

    But, does it bend? After all, that's the point behind fiberoptics, to be able to snake a light beam around corners and through tight spaces so that we don't have to maintain perfect optical alignment over a distance. So, what's the point of this setup? Does it keep moths away by burning them on the outer beams?

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  2. Re:But what does it do? by Anonymous Coward · · Score: 5, Insightful

    air is not transparent and does cause beam scattering. by creating a refractive channel like this they absolutely will reduce beam dispersion. obviously it doesn't eliminate beam spread but even a fiber channel perfectly designed for a single mode will have some diffusion so whats your point?

    they may be able to increase snr by 10^4 over current technologies at 100 m. that's a serious improvement that shouldn't simply be dismissed so thoughtlessly.

  3. Re:What a silly title ... by wiggles · · Score: 3, Insightful

    I'm no expert on this technology, but from tfs, it would seem to increase bandwidth by minimizing loss over distance, allowing for longer range and faster speed.

  4. Re:Perfect to mount by maroberts · · Score: 5, Insightful

    Why is this moderated funny?

    Is this sad, tired old meme actually still genuinely funny in this day and age?

    really?

    Yes.

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