'Optical Fiber' Made Out of Thin Air 115
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.
UMD Link (Score:5, Informative)
Here's a link to the press release from UMD with some links to the professor's web site.
http://cmns.umd.edu/news-events/features/2356 [umd.edu]
Re:What a silly title ... (Score:4, Informative)
Not necessarily - there are lots of situations where it's not practical to run a cable. Secure connectivity between naval vessels is a prime example, others would be for use in the space program, or cheaper data communication between buildings in a campus. Residential broadband internet would be simpler - put an optical transceiver on the roof and point it at a tower - no more digging up the garden to provide fttp.
Yawn (Score:3, Informative)
Predicted the 1960's (Kerr-induced self-focusing: http://journals.aps.org/prl/ab... [aps.org] ), and it was a big part of SDI: http://www.ncbi.nlm.nih.gov/pu... [nih.gov] and was again applied to space-to-ground weapons systems in 2009: http://journals.aps.org/prl/ab... [aps.org]
It was ale demonstrated at LLNL in 2009: http://www.researchgate.net/pu... [researchgate.net] and 2010: http://www.researchgate.net/pu... [researchgate.net]
What's new about this one is that they've renamed the tunnel as the desired artifact, rather than describing it in beams going down the tunnel.