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The 2018 Nobel Prize in physics was awarded on Tuesday to Arthur Ashkin, Gérard Mourou and Donna Strickland for their pioneering work to transform lasers into powerful tools.
Ashkin, a researcher at Bell Laboratories in New Jersey, invented the "optical tweezers" – focused light beams that can be used to capture particles, atoms and even living cells and are now widely used to study the mechanisms of life.
Mourou, from the École Polytechnique in France and the University of Michigan, and Strickland, from the University of Waterloo in Canada, "paved the way" for the most intense laser beams ever created by the man through a technique of stretching and amplification of the light beam. .
"Billions of people use optical disc drives, laser printers and optical scanners every day … millions of people undergo laser surgery," said Nobel Committee member Olga Botner. One of the many examples of so-called blue technology, the discovery of the sky in a basic science can eventually transform our daily lives. "
Strickland is the first woman to receive the Physics Award since 1963, when Maria Goeppert-Mayer was recognized for her work on the structure of nuclei. Marie Curie won the Physics Prize in 1903 and the Nobel Prize in Chemistry in 1911. A reporter asked the teacher how he felt to be the third woman in history to win this award.
"Really, is that all?" I thought there might be more, said Strickland, looking surprised, "Obviously, we have to celebrate the women physicists because we're there. do not know what to say, I'm honored to be one of those women. "
In a laser beam, light waves are tightly focused, rather than mixing and scattering as in ordinary white light. Since the invention of the first laser in 1960, scientists have speculated that the energy from these focused beams could be used to move and manipulate objects – a real-world version of Star Trek's "Tractor Beams".
"But it's been science fiction for a very long time," said committee member Mats Larsson.
Ashkin spent two decades studying the properties of lasers, while recognizing that objects could be attracted to the center of a beam, where radiation was most intense. (A committee member demonstrated this at the press conference using a hairdryer to hang a ping-pong ball in the air.) By focusing the beam further with a lens, he developed a "snare trap". light "which may contain a small spherical object. in place.
Ashkin used his new tool to keep a particle in place, then an atom and finally, in 1987, a living bacterium. Ashkin has even demonstrated that the tool could be used to enter a cell without damaging the living system.
"Of course, it was the real breakthrough, that we could handle such complex objects," Larsson said.
At about the same time, Morou and Strickland were working together at the University of Rochester to solve a persistent problem for decades in the field of laser research: high-intensity laser beams tended to destroy the material used for amplify them. It was as if scientists were trying to boil water in a pan that could not handle such high temperatures.
Rochester researchers have come up with an elegant workaround, which they call "pulsed pulse amplification." They first stretched the beam with a fiber optic cable several kilometers long, reducing its maximum intensity. Then they amplified the signal to the desired level, before compressing it into an ultra-short and ultra-powerful pulse lasting just a fraction of a second.
Strickland was a graduate student at the time; The 1985 article that announced their success was its first scientific publication, according to the Nobel website.
CPA has been used to take process images in a fraction of a second, such as interactions between molecules and atoms. It is also fundamental for laser eye surgery.
"The myriad areas of application have not yet been fully explored," the Nobel Committee said in a statement. to humanity. "
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