By Jacey Fortin

New York Times News Service

Since 1901, when the annual Nobel Prize in physics was first awarded, it has been given almost exclusively to men, year after year. Women had won the award exactly twice.

That changed this week, when the number rose to three. Donna Strickland, a Canadian who is an associate professor of physics at the University of Waterloo, received the prize on Tuesday for her work on high-intensity laser pulses.

Strickland, 59, shared the award with the French physicist Gérard Mourou, 74, with whom she was working as a graduate student when they published a groundbreaking scientific paper in 1985; and Arthur Ashkin, 96, an American scientist who pioneered a way of using light to manipulate physical objects.

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

In an interview with Nobel, the official website of the prize, Strickland said that when she first learned that she had won, she wondered if it might be a prank. “It was just a fun thing to do, and so I enjoyed putting many hours into it,” she said of her work with short-pulse lasers more than 30 years ago.

That work resulted in Strickland’s first published scientific paper in 1985, and she went on to base her doctoral dissertation on it.

Scientists had been trying to figure out how to amplify high-energy laser pulses without destroying the amplifiers. Strickland suggested stretching out the pulses in time, amplifying them and then compressing them again to the desired level of intensity.

Her work with Mourou “paved the way towards the shortest and most intense laser pulses ever created by mankind,” according to Nobel

Their method, known as chirped pulse amplification, allowed for more precision in laser technology and has allowed for several real-world applications, including LASIK eye surgery. Some physicists think it can one day be used to accelerate subatomic particles, just like the Large Hadron Collider.

Strickland, a self-described “laser jock,” was born in Guelph, Ontario, in 1959. Today she runs a laboratory for students at Waterloo called the Ultrafast Laser Group, where one of her favorite activities is to generate a full color spectrum of white light from a narrow bandwidth of wavelengths.

She said her work depended in part on the work of the two women who won the Nobel Prize in physics before her.

Marie Curie was the first woman to win the prize in 1903, for the discovery of radioactivity. (Eight years later, she also won a Nobel Prize in chemistry.) The second was Maria Goeppert Mayer, who won in 1963 for developing a model that could predict the properties of atomic nuclei.

But for 55 years after that, only men won the Nobel Prize in physics. Last year, the nine people who won Nobel Prizes in all three of the scientific categories were men from Western countries.

While women are generally underrepresented in fields like science and technology, the disparities in physics seem to be pronounced, said Rachel Ivie, director of the Statistical Research Center at the American Institute of Physics.

She cited institutional issues that have made it more difficult for women to advance their careers, mentioning maternity leave as one example.

But Ivie added that there seemed to be cultural reasons for the disparities, too, even though women are increasingly represented in the field.

“It hasn’t really caught up yet to the other fields,” she said. “And I think a lot of that is the cultural perception that this is a man’s science, for whatever reason.”