October 17, 2019
On October 24, the Maria Goeppert-Mayer Lectures at the University of Chicago—named in honor of the second woman to win a Nobel Prize in Physics—will feature the third woman to win, 2018 Nobel laureate Prof. Donna Strickland.
Theoretical physicist Maria Goeppert-Mayer developed the nuclear shell model while at UChicago and Argonne National Laboratory from 1946-1960. Because of US regulations at the time, Goeppert-Mayer taught courses at UChicago on a voluntary basis. She won the Nobel for “discoveries concerning nuclear shell structure” in 1963—60 years after Marie Curie became the first female Nobel laureate.
UChicago’s Department of Physics established the annual Maria Goeppert-Mayer Lectures in 2017 to highlight women physicists like Goeppert-Mayer who are shaping and defining their field.
This year’s speaker, Donna Strickland, Professor in the Department of Physics & Astronomy at the University of Waterloo, won the Nobel Prize for developing chirped pulse amplification (CPA) in 1985 with her PhD supervisor at the time, Gérard Mourou. CPA—ultra-short, high-intensity laser pulses—paved the way for the most intense lasers ever created and has broad applications, including laser eye surgery and the machining of small glass parts for cell phones.
We interviewed Strickland about the development of CPA, her admiration for Goeppert-Mayer, and the responsibility of those in power to promote equality in STEM. The conversation has been edited and condensed.
How did you and your PhD supervisor, Gérard Mourou, develop chirped pulse amplification?
Gérard had the idea for more than a year before he gave it to me. We were trying to make a high-intensity laser system, and we were using a different approach that wasn’t working. At the same time, other people were developing fiber pulse compression. They were using fibers to make the extra colors you need for short pulses and found that if you let the fiber be long enough so that the different colors traveling at different speeds could get far enough apart to make a long pulse, it compressed better. Gérard knew we just needed to figure out a way to stretch the pulse, amplify it, and compress it. That’s where I came into it in 1984.
It took me a year to actually build it. There wasn’t any funding at the beginning of the project, so Gérard secured donations of old lasers and fiber. We used leftover light from a laser in another lab that was just going into a beam dump. I took that light, put it in the fiber, and sent the fiber down to the other end of the laser lab. We built an amplifier and then a compressor.
Did you know at that time what the applications for CPA would be?
No, not the ones that are being touted now. We thought it would be a pure science application. We were going to do high-order nonlinear optics and so the application was to try to get out into the UV or XUV with coherent radiation. But I don’t think anyone had thought about the machining glass or cornea applications.
What do you want audiences to take away from your lecture at UChicago?
I think the main point is that lasers changed how light and matter interact. Then CPA came along and changed it again. You don’t actually know what all the applications for your research are. When you change science, you have to go back to drawing board and rethink how things work. That’s what leads to new ideas.
What has Maria Goeppert-Mayer’s work meant to you?
What she won the Nobel Prize for—the nuclear shell model—I know nothing about. It was her PhD research that I was familiar with. She started this whole new field that we now call multiphoton physics. She was the first one to lay down the quantum mechanics of the process itself. That’s the paper that I cited in my PhD, but I also didn’t know she was a woman back then. It was just a name and, at the time, it was automatic for me to use the pronoun he. One of my supervisors, a theorist, read the thesis and gave it back to me with a big red mark over the he. He said, “Shame on you, Donna.” Since then, I’ve read about her. I think it’s remarkable that she didn’t get paid as a scientist for most of her career. As a person growing up when I did, that was inconceivable. The fact she was willing to do it for the straight love of science is truly remarkable.
After you won the Nobel, you told the Guardian that you were surprised by how much the “big story” had become about your gender and not the science. What do you think can be done to change that narrative?
I thought it was so funny that people were asking me why only three women had won the Nobel, when for a century, the men had the power to give these away. I recently gave a speech where I pointed out that Pierre Curie made a stand and didn’t accept the award without it also going to Marie. I think it has to be men who stand up and say something. At Waterloo, we’re proud to be part of the UN’s HeForShe campaign. It’s about the people in power standing up to make sure everyone is looked after and treated equally.