Did someone post this already?

http://science.nasa.gov/headlines/y2003/25jul_colloids.htm?list818490

"...Now researchers at Harvard University have
developed a new way of steering and manipulating light
beams.

"Using droplets of liquid crystals--the same substance
in laptop displays--the scientists can make a pane of
glass that quickly switches from transparent to
diffracting and back again. When the pane is
transparent a laser beam passes straight through, but
when the pane is diffracting, it splits the beam,
bending it in several new directions.

"The change is triggered by applying an electric
field, so the pane could easily be controlled by the
electric signals of a computer, offering a powerful
new way to steer beams of light...

"...A technique invented by Weitz and his colleagues
produces equal-sized droplets of liquid crystal, each
about a dozen microns across (a micron is one
thousandth of a millimeter). Because they're all the
same size, packing the droplets together on a glass
plate causes them to arrange themselves into a
honeycomb pattern.

"It's this regular pattern that gives sheets of liquid
crystal droplets their light-steering ability...

"..."The big difference between what we do and what
has been done before is that older-style glass panes
contain a random distribution of drops and drop
sizes--tiny ones and big ones. They're not ordered at
all," explains Darren Link, one of the scientists on
the research team.

"Without any order in the drop size and spacing, these
older liquid crystal systems simply scatter light in
all directions--hence the frosted-glass effect. 

""In our case, because we make all the drops the same
size, we're able to steer light in specific
directions," Link says..."

At the bottom of this article are links to more
technical ones.

Debbi

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