Donald Umstadter and Wenchao Yan
A rendering of how changes in an electron’s motion (bottom) alter the scattering of light (top), as measured in a new experiment that scattered more than 500 photons of light from a single electron. Previous experiments had managed to scatter no more than a few photons at a time.
Physicists from the University of Nebraska-Lincoln are seeing an everyday phenomenon in a new light.
By focusing laser light to a brightness 1 billion times greater than the surface of the sun — the brightest light ever produced on Earth — the physicists have observed changes in a vision-enabling interaction between light and matter.
Those changes yielded unique X-ray pulses with the potential to generate extremely high-resolution imagery useful for medical, engineering, scientific and security purposes. The team’s findings, detailed June 26 in the journal Nature Photonics, should also help inform future experiments involving high-intensity lasers.
Donald Umstadter and colleagues at the university’s Extreme Light Laboratory fired their Diocles Laser at helium-suspended electrons to measure how the laser’s photons — considered both particles and waves of light — scattered from a single electron after striking it.
Under typical conditions, as when light from a bulb or the sun strikes a surface, that scattering phenomenon makes vision possible. But an electron — the negatively charged particle present in matter-forming atoms — normally scatters just one photon of light at a time. And the average electron rarely enjoys even that privilege, Umstadter said, getting struck only once every four months or so.
Though previous laser-based experiments had scattered a few photons from the same electron, Umstadter’s team managed to scatter nearly 1,000 photons at a time. At the ultra-high intensities produced by the laser, both the photons and electron behaved much differently than usual.
“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 Umstadter, the Leland and Dorothy Olson Professor of Physics and Astronomy.
A photon from standard light will typically scatter at the same angle and energy it featured before striking the electron, regardless of how bright its light might be. Yet Umstadter’s team found that, above a certain threshold, the laser’s brightness altered the angle, shape and wavelength of that scattered light.
“So it’s as if things appear differently as you turn up the brightness of the light, which is not something you normally would experience,” Umstadter said. “(An object) normally becomes brighter, but otherwise, it looks just like it did with a lower light level. But here, the light is changing (the object’s) appearance. The light’s coming off at different angles, with different colors, depending on how bright it is.”
That phenomenon stemmed partly from a change in the electron, which abandoned its usual up-and-down motion in favor of a figure-8 flight pattern. As it would under normal conditions, the electron also ejected its own photon, which was jarred loose by the energy of the incoming photons. But the researchers found that the ejected photon absorbed the collective energy of all the scattered photons, granting it the energy and wavelength of an X-ray.
The unique properties of that X-ray might be applied in multiple ways, Umstadter said. Its extreme but narrow range of energy, combined with its extraordinarily short duration, could help generate three-dimensional images on the nanoscopic scale while reducing the dose necessary to produce them.
Those qualities might qualify it to hunt for tumors or microfractures that elude conventional X-rays, map the molecular landscapes of nanoscopic materials now finding their way into semiconductor technology, or detect increasingly sophisticated threats at security checkpoints. Atomic and molecular physicists could also employ the X-ray as a form of ultrafast camera to capture snapshots of electron motion or chemical reactions.
As physicists themselves, Umstadter and his colleagues also expressed excitement for the scientific implications of their experiment. By establishing a relationship between the laser’s brightness and the properties of its scattered light, the team confirmed a recently proposed method for measuring a laser’s peak intensity. The study also supported several longstanding hypotheses that technological limitations had kept physicists from directly testing.
“There were many theories, for many years, that had never been tested in the lab, because we never had a bright-enough light source to actually do the experiment,” Umstadter said. “There were various predictions for what would happen, and we have confirmed some of those predictions.
“It’s all part of what we call electrodynamics. There are textbooks on classical electrodynamics that all physicists learn. So this, in a sense, was really a textbook experiment.”
Learn more: 1 billion suns: World’s brightest laser sparks new behavior in light
The Latest on: Laser intensity
- Russians reportedly building a satellite-blinding laser — an expert explains the technologyon August 2, 2022 at 11:00 am
Laser technology has evolved to the point where this type of anti-satellite defense is plausible, though there is limited evidence of any nation successfully testing such a laser.
- New Laser Technology Could Cut Bird Strikes At Airportson August 1, 2022 at 9:31 am
The AI makes decisions on target detection, tracking, aiming and firing, while the video camera captures real-time images of the assigned airspace.
- Russians is reportedly building a satellite-blinding laser — an expert explains the techon July 31, 2022 at 10:00 pm
Russia is building a new ground-based laser facility for interfering with satellites orbiting overhead, according to a recent report in The Space Review. The basic idea would be to dazzle the optical ...
- Hands On With The Ortur Laser Cutteron July 30, 2022 at 5:00 pm
The Ortur Laser Master 2 is reasonably priced and has ... no modulation of beam intensity). The best way to see how to build the machine is to watch the company’s video instructions (see below).
- Chinese scientists build bird-zapping laser to guard airportson July 30, 2022 at 3:00 am
The AI-driven system fires a painful but non-lethal beam at birds, which pose a high risk to aircraft, but experts raise concerns over potential effects on pilots and endangered species.
- Russia’s reportedly building a satellite-blinding laser — an expert explains what that meanson July 29, 2022 at 12:22 am
Depending on the photon intensity and wavelength, the directed beam of energy formed by a laser can create a range of effects at its target. For example, if the photons are in the visible part of ...
- Novel Laser Tracking Stations Could Help Reduce Space Debris Collisionson July 29, 2022 at 12:22 am
In a pre-proof article posted in the Journal of Space Safety Engineering, researchers discussed and demonstrated the accomplishments of a conceptual study on the potential advancement made in the ...
- Russia Building A Satellite-Blinding Laser Weaponon July 26, 2022 at 9:52 pm
Russia is building a new ground-based laser facility for interfering with satellites orbiting overhead, according to a recent report in The Space ...
- This high-powered laser can ‘write’ in thin airon July 26, 2022 at 5:15 am
Chinese scientists have achieved this using a high-powered laser that can write in thin air. Yes, right in thin air. This was made possible by a team of scientists led by Cao Xiangdong. Cao and his ...
- Your Complete Guide to CO2 Laser Resurfacingon July 21, 2022 at 5:00 pm
You may need more than one treatment session, depending on the treatment required and intensity of the laser used. Loose skin above the upper and lower eyelids can cause what’s commonly known as ...
via Google News and Bing News