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- ALBUQUERQUE, N.M. -- On the heels of his July 16 Nature paper about improving
night vision devices with an artificial lattice that efficiently bends
infrared light (see write-up, photos at http://www.sandia.gov), Sandia
National Laboratories scientist Shawn Lin strikes again in a paper in today's
(Oct. 9, 1998) issue of the journal Science.
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- In it, Lin explains how he and colleagues
used a larger, simpler lattice to bend microwaves around 90-degree corners,
within radii smaller than a wavelength, and with almost 100 percent transmission
efficiency.
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- The achievement -- like turning a hippopotamus
on a dime -- lays groundwork for more accurately directed, lighter-weight
microwave communications. It also provides proof of principle that similar
structures would be effective at the much shorter wavelengths of long-distance
optical communications and, potentially, optical computing, by making possible
far cheaper, smaller, more efficient electromagnetic wave containers and
guides than any known.
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- These artificial lattices, known as photonic
crystals, guide electromagnetic radiation by a method fundamentally different
from traditional index-of-refraction techniques. Waves are trapped in column-like
arrays that --when fabricated to appropriate dimensions -- reflect desirable
wavelengths as mirrors do light. Transmission is achieved through use of
deliberately added defects, which act as wave guides.
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- The microwave work, achieved in two dimensions,
was a collaboration with Sandia researchers Edmond Chow and Vincent Hietala,
and physicists Pierre Villeneuve and J.D. Joannopoulos of the Massachusetts
Institute of Technology.
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- Sandia is a multiprogram U.S. Department
of Energy laboratory, operated by a subsidiary of Lockheed Martin Corp.
With main facilities in Albuquerque, N.M., and Livermore, Calif., Sandia
has major research and development responsibilities in national security,
energy, and environmental technologies.
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