fb-pixel Skip to main content

Nobel Prize in physics awarded to scientists who put light to work

Professor Donna Strickland was applauded at a news conference at the University of Waterloo.
Professor Donna Strickland was applauded at a news conference at the University of Waterloo. Cole Burston/Getty Images

NEW YORK — The 2018 Nobel Prize in physics was awarded Tuesday to Arthur Ashkin of the United States, Gérard Mourou of France, and Donna Strickland of Canada for harnessing one of the most ineffable aspects of nature, pure light, into a mighty microscopic force. Strickland, a self-described “laser jock,” is only the third woman to win the physics prize, for work she did as a graduate student with Mourou.

Ashkin will receive half of the monetary prize, worth about $1 million; Mourou and Strickland will split the remainder.

The Nobel committee recognized the scientists for their work in transforming laser light into miniature tools. Ashkin invented “optical tweezers,” which use the pressure from a highly focused laser beam to manipulate microscopic objects, including living organisms such as viruses and bacteria.


Strickland and Mourou developed a method of generating high-intensity, ultrashort laser pulses, known as chirped pulse amplification. The work has had a wide range of real-world applications, enabling manufacturers to drill tiny, precise holes and allowing for the invention of LASIK eye surgery.

Some physicists think that chirped pulse amplification eventually will be employed to accelerate subatomic particles, replacing giant contraptions such as the Large Hadron Collider with tabletop experiments. In the physics of tomorrow, “bigger is not necessarily better,” said Robbert Dijkgraaf, director of the Institute for Advanced Study in Princeton, N.J.

In a telephone news conference, Strickland expressed hope that chirped pulse amplification might one day be used to cure cancer. Ashkin’s optical tweezers have been especially important in biological research on viruses and other microbes.

Ashkin, born in 1922 in New York City, earned an undergraduate degree in physics from Columbia in 1947. He received a doctorate in nuclear physics from Cornell in 1952 and joined Bell Labs, the longtime hotbed of innovation and Nobel Prizes, in Murray Hill, N.J., where he worked until 1991.


Ashkin began experimenting with lasers — beams of coherent monochromatic light waves marching in unison like toy soldiers — in the 1960s, shortly after they were invented. The same light pressure that sweeps from a comet’s tail, he figured, could be used in the lab to push a microscopic ball around.

To his amazement, the play of forces within the laser beam actually drew the ball into the center of the beam and trapped it there — a first step toward optical tweezers.

“Optical tweezers were not an invention, they were a surprise,” said David G. Grier, a physicist at New York University and a former colleague of Ashkin at Bell Labs. “That was a new thought for science, that light can pull. It is revolutionary.”

In 1997, Steven Chu, who had worked with Ashkin at Bell Labs and is now at Stanford University, won the physics prize for using optical tweezers to investigate the quantum mechanical properties of atoms. Ashkin later said he was disappointed that he had not been included in the award.

With his own tweezers, Ashkin went on to investigate the inner workings of cells and the molecular motors that power tiny organisms. He is still at it. After Tuesday’s announcement, the Royal Swedish Academy of Sciences said that Ashkin, who turned 96 last month, would not be available for comment because he was busy with his next scientific paper.

Mourou was born in Albertville, France, in 1944 and earned a doctorate in physics from the University of Grenoble in 1973. Currently he is a professor at the École Polytechnique in France and director of the International Center for Zetta-Exawatt Science and Technology, which is devoted to the study of high-intensity, ultrafast laser pulses.


Mourou spent 30 years in the United States at the University of Michigan, where he remains an emeritus professor, and at the University of Rochester. It was at the latter school that he took on Strickland as a graduate student.

The research that won them the Nobel was her first-ever scientific paper, published in December 1985.

Experimenters were at a loss for how to amplify high-energy laser pulses without wrecking their amplifiers. Strickland suggested stretching out the pulses in time, amplifying them and then compressing them again.

The process generates intense laser pulses that last only a femtosecond — one millionth of a billionth of a second, the amount of time it takes a light wave to traverse the width of a human hair.

Strickland, who was born in Guelph, Canada, in 1959, is only the third woman to win the Nobel Prize for Physics. She is now an associate professor at the University of Waterloo in Canada.

The Nobel prizes have come under criticism in recent years for the lack of female laureates. Among the overlooked candidates often mentioned is Jocelyn Bell Burnell, who discovered pulsars as a graduate student at Cambridge University in 1968 but was not included in a Nobel Prize that was subsequently awarded to her adviser, astronomer Antony Hewish.


Strickland sounded surprised when she was asked how it felt to be only the third female Nobel winner for physics. “I thought it might have been more than that,” she said. “I don’t know what to say.”

The Royal Academy announced last week that it was changing its nominating guidelines to try to ensure greater diversity of winners in the future, but said these measures had not affected Tuesday’s award.

“Yes, it’s great,” Lisa Randall, a theoretical physicist at Harvard, said in an e-mail of Strickland’s prize. “My guess is they were listening.”

Who won the 2017 physics Nobel?

Rainer Weiss, Kip Thorne and Barry Barish were recognized for the detection of ripples in space-time known as gravitational waves, which were predicted by Albert Einstein a century ago but had never been directly seen. The Royal Swedish Academy called it “a discovery that shook the world.”

James P. Allison and Tasuku Honjo were awarded the Nobel Prize in physiology or medicine on Monday, for a discovery that the body’s immune system can be used to attack cancer cells.

When will the other Nobels be announced?

■  The Nobel Prize in chemistry will be announced Wednesday in Sweden.

■  The Nobel Peace Prize will be announced Friday in Norway.

■  The Nobel Memorial Prize in Economic Science will be announced Monday in Sweden.

■  The Nobel Prize in literature has been postponed. The institution that chooses the laureate is embroiled in a scandal involving allegations of sexual misconduct, financial malpractice and repeated leaks — a crisis that led to the departure of several board members and required the intervention of the king of Sweden. Two laureates might be announced next year.