Paul Corkum: pioneer of making molecules take images of themselves
"Waves are everywhere in physics," explains Dr. Paul Corkum. "Everything is made of electrons and nuclei, and both have wave properties. Electrons are pulled strongly to the much heavier nuclei. In a molecule or solid, electrons must move only a short distance before the forces on the electron change. Therefore, electrons live in a world where changes occur very rapidly—in attoseconds."
Dr. Corkum is an attosecond scientist. He discovered ways to make and measure pulses of light that last a very, very short time—a time so short that it's measured in attoseconds. In fact, attosecond light pulses last the shortest length of time of any event that we, humans, can control. An attosecond is 1 billionth of a billionth of a second. Think of it like this: 1 attosecond is to 1 second as 1 second is to the age of the universe.
The discovery of attosecond light pulses allowed scientists to capture the movement of electrons and observe molecular reactions as they occur. Dr. Corkum's research brings physicists a big step closer to measuring and controlling the movements of electrons as they speed through molecules or solids.
Light has 2 parts: the electric force and the magnetic force. These 2 forces (sometimes called fields to emphasize that the force can be felt everywhere) interplay in light, but usually the electric force dominates.
Dr. Corkum is an international expert in strong-field atomic physics. His ground-breaking work in attosecond science is key to the strategic partnership between the National Research Council of Canada (NRC) and the University of Ottawa (uOttawa). He divides his research time between the Advanced Research Complex (ARC) at uOttawa and the NRC–uOttawa Joint Attosecond Science Laboratory.
Another breakthrough was when Dr. Corkum and Dr. Ferenc Krausz became the first to successfully produce sub-femtosecond (or attosecond) pulses: incredibly short flashes of light that allow scientists to capture the movement of electrons and observe molecular reactions as they occur. With this work, Dr. Corkum's vision of how to make and measure the world's shortest pulses went from an idea to practical reality.
Dr. Corkum has worked with many postdoctoral researchers in his 50 years at the NRC, including Dr. Donna Strickland, a recipient of the Nobel Prize in Physics in 2018 and a professor at the University of Waterloo.
"I decided in my third year of graduate school that I would become Dr. Corkum's second postdoc when I finished my studies. Dr. Corkum was already Canada's leading researcher in ultrafast optics and was doing really interesting experiments in his lab," said Dr. Strickland. "Luckily for me, Dr. Corkum agreed that I be his postdoc, so I had 3 great years working with him, first studying why focusing short pulses into anything clear, such as water, creates all of the colours of the rainbow. We then also blew up molecules with the short laser pulses to determine the interaction process between matter and very intense light. What I learned most from him was that you really learn science by talking about it with your colleagues."
Originally from Saint John, New Brunswick, Dr. Paul Corkum obtained his BSc (1965) from Acadia University in Nova Scotia and his MSc (1967) and PhD (1972) in theoretical physics from Lehigh University in Pennsylvania. He started his career as a theoretical physicist but changed to experimental physics when he arrived at the NRC as a postdoctoral fellow in 1973. He joined the University of Ottawa in 2008 and is currently a professor in the Department of Physics there, co-director of the Max Planck–uOttawa Centre and a retired principal research officer at the NRC.
One of his colleagues at the NRC, Dr. David Villeneuve, Principal Research Scientist and the W.G. Schneider Medal recipient for 2023, says, "Dr. Corkum has an infectious enthusiasm for science. He likes nothing better than to have a group of scientists gather around the whiteboard in his office and argue the finer points of physics. Dr. Corkum is always able to see through the details of complex experiments and find the underlying gold nugget at its centre. Then he's able to jump ahead and visualize the implications of the observations."
Researcher and scholar, Dr. Corkum has received numerous prizes over the course of his career. In 2007, he was awarded with the John C. Polanyi Award, and in 2008, he received the Gerhard Herzberg Canada Gold Medal for Science and Engineering. In 2013, he received several prestigious awards and professional honours, including the Harvey Prize for his contributions to the field of attosecond science, the King Faisal International Prize for Science and the Royal Photographic Society's Progress Medal. In 2014, he received the Frederic Ives Medal, the highest award given by the Optical Society of America. In 2015, he received the Lomonosov Gold Medal—the premier award of the Russian Academy of Science—and, in October 2017, he was awarded a Royal Medal by the Royal Society of the United Kingdom.
In early 2022, he received the Wolf Prize in Physics alongside his European colleagues Dr. Anne L'Huillier and Dr. Ferenc Krausz for their pioneering contributions to ultrafast laser science and attosecond physics. In the spring of 2023, Dr. Corkum and his colleagues were again recognized, this time with the Frontiers of Knowledge Award, for their observations of subatomic processes unfolding over the shortest time scale captured by science. Their discoveries could lead to advances in telecommunications, computing, engineering and medicine.