Jun 28, 2017

This laser is a billion times brighter than the sun

University of Nebraska - Lincoln

Researchers just discovered that some very strange things happen to electrons when they are hit with a laser with the power of a billion suns. The electrons changed their own path when hit by the laser, and then altered the way in which photons of light scattered once they bounced off.

Why it matters: This second effect (the scattering of photons of light, which is the basis for how we "see" things) could fundamentally alter our understanding of vision and the way in which light and matter interact, the researchers said in Nature Photonics. The use of intense light could also allow researchers to detect cancerous tumors or micro-fractures that x-rays might miss.

What they did: While physicists have theorized what might happen when intensely bright light interacts with electrons, this is the first time that a laser was powerful enough to trigger reactions that had only been previously theoretical. The laser used in this experiment is the brightest light ever produced on Earth.

Researchers observed that both electrons and photons behave much, much differently when they're part of an intensely bright light. Usually, for instance, one photon of light will bounce off one electron at a time. Here, a thousand photons bounced off just one electron. At ordinary levels of light, photons also bounce off electrons in the same direction and with the same energy. Not the case here. Beyond a critical threshold, the intense laser's brightness changed the angle, shape and wavelength of the photons as the light scattered – effectively changing the nature of what is visible under such intensity.

"When we have this unimaginably bright light, it turns out that the scattering — this fundamental thing that makes everything visible - fundamentally changes in nature," said University of Nebraska physicist Donald Umstadter.

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