Science

Nano antenna amplifies light by a factor of 1,000

A rendering of the nanoantenna
A rendering of the nanoantenna
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The gold tips of the nanoantenna
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The gold tips of the nanoantenna
A rendering of the nanoantenna
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A rendering of the nanoantenna

Scientists at Houston’s Rice University have successfully increased the intensity of laser light a thousand-fold by shining it into a “nanoantenna.” At the heart of the device are two gold tips, separated by a gap measuring about a hundred-thousandth the width of a human hair. At the point where it passed through that gap, the light was “grabbed” and concentrated. Condensed matter physicist Doug Natelson believes that the technology could be useful in the development of tools for optics and chemical/biological sensing, with applications in industrial safety, defense and homeland security.

The photons in the laser light excited plasmons (oscillating electrons) in the gold tips, creating an electrical field within the gap. “At the surfaces of the metal, these fields can be very big – much bigger than those from the original radiation,” Natelson explained. “What was hard to measure was just how big.”

The gold tips of the nanoantenna
The gold tips of the nanoantenna

In order to obtain those measurements, the Rice team started by running a low-voltage, controllable current into the antenna, which caused electrons to jump across the gap. By comparing the the low-frequency electrically driven and the high-frequency optically driven currents between the tips, the researchers were able to set a standard by which the light amplification could be measured.

“The reason we're studying these enhanced fields is not just because they're there,” Natelson said. “If you can enhance the local field by a factor of 1,000, there are lots of things you can do in terms of sensors and non-linear optics. Anything that gives you a handle on what's happening at these tiny scales is very useful.”

4 comments
BoilingOil
Imagine being able to use this in ordinary lighting applications: replacing a 100W lightbulb with a 100mW one. Now THAT\'s good news! And with LED lighting, even 10-20mW might be sufficient!
Neon
Finally!! Lazer Rifles can now be a reality
Facebook User
OMG. I have been thinking about biologic molecules and the possibilities of bose - einstein condensates in that environment. Could the above described fields possibly control electrons and spacial sheet distributions to allow protons to \"tunnel\" at low energy levels (the focus of my thinking) thus allowing the proposed biotransmutation for which lab evidence supposedly has been gathering a few centuries? As the fellow said on the totally unrelated radio program- it\'s not what physics can tell us about biology, but what biology can tell us about physics. Nano, wasn\'t Ma nature the first \"developer\" on that scale?
GeoMoon5
I wonder if this new information could be used to create a super energy efficient \"pico projector\" for mobile devices, or maybe a projection device integrated into glasses to allow for a personal heads up display environment.