What would you do if you woke up one day and your whole life changed?
Forty years ago, when Donna Strickland, physics professor at the University of Waterloo, and Gérard Mourou published their paper on the discovery of chirped pulse amplification (CPA), they knew they had found something that would change laser science. Fast forward 33 years to an early morning call from the Nobel organization with news of her 2018 Nobel Prize win, and Strickland's life was changed forever.
What followed was a whirlwind of press interviews, travel, and lectures around the globe. As the third woman ever to win a Nobel Prize, Strickland became a household name overnight. And she deserved it.
Physics laureate Donna Strickland receives the prize from King Carl Gustaf of Sweden during the Nobel Prize award ceremony in Stockholm on December 10, 2018.
The invention of the CPA technique changed the game in laser science. Its creation enabled a giant leap in the intensity of optical pulses that continue to steadily climb. Thanks to Strickland and her PhD supervisor, Mourou, countless everyday technologies became possible, built on research propelled by this groundbreaking technique.
While lasers were invented in 1960, no one had figured out how to amplify short laser pulses without damaging their laser amplifiers in the two decades after. Strickland and Mourou discovered that if they stretched the pulse, amplified it, and then compressed it back down, they could heighten the laser's intensity without damaging the amplifier. The breakthrough approach packed more light into a shorter time, which increased the intensity of the pulse and allowed the laser beams to cut into matter with precision.
"When you make the intensity extremely high, you have a laser hammer, and not only is it a hammer, but it can hammer through transparent objects like your cornea or like glass in your telephone," Strickland says. "Before this laser, you could not machine glass because the light went right through it, but after CPA created this laser hammer, you could."
The ripple effect of that laser hammer is significant. Strickland and Mourou's breakthrough sparked research that has led to many of the technologies we now use daily. CPA is used to slice open the cornea of the eye without damaging the surrounding tissue, making the process of laser eye surgery far less painful for patients. It also has applications in many laser materials processing techniques, including the machining of fragile materials like the glass used in smartphones. Additionally, CPA can be used to accelerate protons that could one day be used in proton therapies used to treat deep-tissue tumors, like those in the brain.
Since winning the Nobel Prize, Strickland continues to push the boundaries in laser science to make new discoveries that have the potential to further impact many industries.
"Now what I'm trying to do is make pulses even shorter," she says. "To do that, I'm making a rainbow of colours in my lab so that I can generate an even shorter pulse. And we're also trying to make the laser lase out of mid infrared, which will hopefully be used to benefit the environment, but more to come on that."
If you ask Strickland, she'll say she gets too much credit for some modern inventions using CPA. Here at Waterloo, we think it's just the right amount for her Nobel Prize-winning work.
Kind words from Waterloo colleagues
"All of the experimental work I have done for the past thirty years has relied on the technology developed by Donna and almost everyone in the field of ultrafast laser matter interactions could say the same." - Joe Sanderson
"The development of laser technologies possible because of CPA has unlocked our ability to probe, control, and characterize matter via spectroscopy and dynamics. Applications range from surgery and micromachining through to taking split-second pictures of atoms in molecules." - Scott Hopkins
"CPA was a giant leap for laser science. Suddenly, femtosecond pulses could be amplified without blowing up the gain medium what a game-changer. Anytime I talk about this in a lecture, I tell my students: "This paper here? Co-authored by my colleague Donna Strickland. Yes, our Donna in Physics. And yes, it's one of the most cited and influential papers in laser physics." And yes, I was doing this years before Donna and Gerard Mourou received the Nobel Prize." - German Sciaini
