ACM TechNews
New Technique to Compress Light Could Open Doors for Optical Communications
University of California, Berkeley (07/30/08) Tompa, Rachel
University of California, Berkeley scientists have developed a way of
compressing light that could enable the development of new technologies in
optical communications, miniature lasers, and optical computers. Berkeley
researchers, led by professor Xiang Zhang, have developed a way of
confining light to spaces only 10 nanometers wide, just five times the
width of a single piece of DNA and more than 100 times thinner than current
optical fibers. "There has been a lot of interest in scaling down optical
devices," Zhang says. "It's the holy grail for the future of
communications." Rupert Oulton, a research associate in Zhang's group,
says that ideally optics researchers would like to squeeze light down to
the size of electron wavelengths to create better cooperation between light
and matter. However, such efforts are hindered when light is compressed
farther than its wavelength, because light does not want to stay inside a
space that small, Oulton says. Researchers have been able to compress
light beyond its limits by using surface plasmonics, where light binds to
electrons allowing it to propagate along the surface of metal. However,
the waves can only travel short distances along the metal before
diminishing. Oulton was working on combining plasmonics and
semiconductors, which have even more pronounced losses, when he thought of
a new technique. Oulton ran simulations to test the idea, and found that
not only could light be compressed just tens of nanometers wide, but it
could travel distances nearly 100 times greater than in conventional
surface plasmonics alone. "This technique could give us remarkable control
over light," Oulton says. "And that would spell out amazing things for the
future in terms of what we could do with that light."
http://berkeley.edu/news/media/releases/2008/07/30_focusinglight.shtml
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