Curving laser “light bullets” may help scientists monitor air pollution

April 10th, 2009 - 2:53 pm ICT by ANI  

National Geographic Washington, April 10 (ANI): A new study has determined that laser “light bullets” that can curve through the air might someday help scientists monitor air pollution.

The bullets are created by extremely short-duration, high-intensity laser pulses, lead study author Pavel Polynkin, a physicist at the University of Arizona, US, told the National Geographic News.

The pulses are so rapid that the beam is broader than it is wide-creating what Polynkin calls “pancakes” of light.

But, the use of complex lasers that produce wave patterns called airy beams causes the brightest part of the beam to bend as the pancake of light speeds away.

The super-brightness of the laser can also cause the pancake to change shape as it moves through air, according to Polynkin.

“If the intensity exceeds a threshold, then the beam tends to self-focus-the pancake wants to become a very short needle,” he said.

Within that needle, the light intensity gets so high that the air around it becomes electrically charged, briefly creating a conductive path of plasma.

Previous work suggested that such light bullets could be used to create human-induced lightning, which has implications for lightning control around sensitive structures such as tall buildings and airplanes.

When combined with the Airy beams, these plasma-producing lasers can also create curving “needle” bullets that might have other uses, Polynkin’s study has suggested.

According to Polynkin, the light pulses leave behind curving plasma trails that emit their own light, providing a way to monitor air pollution in the upper atmosphere without the need for airplanes or weather balloons.

Shot into the sky, these light trails would illuminate the chemical signatures of atmospheric pollutants, which can then be recorded remotely. (ANI)

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