[cmslabstudent] Fwd: ChenWeiguang - Press Release from the University of Rochester
- From: Weiguang Chen <chenweiguang82@xxxxxxxxx>
- To: cmslabstudent@xxxxxxxxxxxxx
- Date: Thu, 4 Jun 2009 15:42:33 +0800
---------- Forwarded message ----------
From: University of Rochester Communications <
nobody@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>
Date: Thu, Jun 4, 2009 at 1:49 PM
Subject: ChenWeiguang - Press Release from the University of Rochester
To: chenweiguang82@xxxxxxx
ChenWeiguang thought you might be interested in this story from the
University of Rochester.
MEDIA CONTACT: Jonathan Sherwood *jonathan.sherwood@xxxxxxxxxxxxx*
585.273.4726
*May 29, 2009*
Regular Light Bulbs Made Super-Efficient with Ultra-Fast Laser
*Laser Process Doubles Brightness for the Same Amount of Energy*
An ultra-powerful laser can turn regular incandescent light bulbs into
power-sippers, say optics researchers at the University of Rochester. The
process could make a light as bright as a 100-watt bulb consume less
electricity than a 60-watt bulb while remaining far cheaper and radiating a
more pleasant light than a fluorescent bulb can.
The laser process creates a unique array of nano- and micro-scale structures
on the surface of a regular tungsten filament—the tiny wire inside a light
bulb—and theses structures make the tungsten become far more effective at
radiating light.
The findings will be published in an upcoming issue of the journal *Physical
Review Letters*.
\\"We\\'ve been experimenting with the way ultra-fast lasers change metals,
and we wondered what would happen if we trained the laser on a filament,\\"
says Chunlei Guo, associate professor of optics at the University of
Rochester. \\"We fired the laser beam right through the glass of the bulb
and altered a small area on the filament. When we lit the bulb, we could
actually see this one patch was clearly brighter than the rest of the
filament, but there was no change in the bulb\\'s energy usage.\\"
The key to creating the super-filament is an ultra-brief, ultra-intense beam
of light called a femtosecond laser pulse. The laser burst lasts only a few
quadrillionths of a second. To get a grasp of that kind of speed, consider
that a femtosecond is to a second what a second is to about 32 million
years. During its brief burst, Guo\\'s laser unleashes as much power as the
entire grid of North America onto a spot the size of a needle point. That
intense blast forces the surface of the metal to form nanostructures and
microstructures that dramatically alter how efficiently light can radiate
from the filament.
In 2006, Guo and his assistant, Anatoliy Vorobyev, used a similar laser
process to turn any metal pitch black. The surface structures created on the
metal were incredibly effective at capturing incoming radiation, such as
light.
\\"There is a very interesting \\'take more, give more\\' law in nature
governing the amount of light going in and coming out of a material,\\" says
Guo. Since the black metal was extremely good at absorbing light, he and
Vorobyev set out to study the reverse process—that the blackened filament
would radiate light more effectively as well.
\\"We knew it should work in theory,\\" says Guo, \\"but we were still
surprised when we turned up the power on this bulb and saw just how much
brighter the processed spot was.\\"
In addition to increasing the brightness of a bulb, Guo\\'s process can be
used to tune the color of the light as well. In 2008, his team used a
similar process to change the color of nearly any metal to blue, golden, and
gray, in addition to the black he\\'d already accomplished. Guo and Vorobyev
used that knowledge of how to control the size and shape of the
nanostructures—and thus what colors of light those structures absorb and
radiate—to change the amount of each wavelength of light the tungsten
filament radiates. Though Guo cannot yet make a simple bulb shine pure blue,
for instance, he can change the overall radiated spectrum so that the
tungsten, which normally radiates a yellowish light, could radiate a more
purely white light.
Guo\\'s team has even been able to make a filament radiate partially
polarized light, which until now has been impossible to do without special
filters that reduce the bulb\\'s efficiency. By creating nanostructures in
tight, parallel rows, some light that emits from the filament becomes
polarized.
The team is now working to discover what other aspects of a common light
bulb they might be able to control. Fortunately, despite the incredible
intensity involved, the femtosecond laser can be powered by a simple wall
outlet, meaning that when the process is refined, implementing it to augment
regular light bulbs should be relatively simple.
Guo is also announcing this month in *Applied Physics Letters* a technique
using a similar femtosecond laser process to make a piece of metal
automatically move liquid around its surface, even lifting a liquid up
against gravity.
This research was supported by the U.S. Air Force Office of Scientific
Research.
About the University of Rochester
The University of Rochester (www.rochester.edu) is one of the nation's
leading private universities. Located in Rochester, N.Y., the University
gives students exceptional opportunities for interdisciplinary study and
close collaboration with faculty through its unique cluster-based
curriculum. Its College of Arts, Sciences, and Engineering is complemented
by the Eastman School of Music, Simon School of Business, Warner School of
Education, Laboratory for Laser Energetics, Schools of Medicine and Nursing,
and the Memorial Art Gallery.
PR 3385, MS -1
--
Best Wishes
ChenWeiguang
************************************************
# Chen, Weiguang
#
# Postgraduate, Ph. D
# 75 University Road, Physics Buliding # 218
# School of Physics & Engineering
# Zhengzhou University
# Zhengzhou, Henan 450052 CHINA
#
# Tel: 86-13203730117;
# E-mail:chenweiguang82@xxxxxxxxx <E-mail%3Achenweiguang82@xxxxxxxxx>;
# chenweiguang82@xxxxxx
#**********************************************
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