The American physicist Arthur Ashkin, Gérard Mourou from France, and Donna Strickland in Canada will share the 9M Swedish kronor (£770,000) prize announced by the Royal Swedish Academy of Sciences in Stockholm on Tuesday. Strickland is the first female physics laureate for 55 years.
The Royal Swedish Academy of Sciences has decided to award the Nobel Prize in Physics 2018 “for groundbreaking inventions in the field of laser physics” with one half to Arthur Ashkin “for the optical tweezers and their application to biological systems” and the other half jointly to Gérard Mourou and Donna Strickland “for their method of generating high-intensity, ultra-short optical pulses.”
Optical tweezers (originally called “single-beam gradient force trap”) are scientific instruments that use a highly focused laser beam to provide an attractive or repulsive force (typically on the order of piconewtons), depending on the relative refractive index between particle and surrounding medium, to physically hold and move microscopic objects similar to tweezers. They are able to trap and manipulate small particles, typically order of micron in size, including dielectric and absorbing particles. Optical tweezers have been particularly successful in studying a variety of biological systems in recent years.
The inventions being honoured this year have revolutionised laser physics. Extremely small objects and incredibly fast processes now appear in a new light. Not only physics, but also chemistry, biology and medicine have gained precision instruments for use in basic research and practical applications.
Arthur Ashkin (born September 2, 1922) is an American scientist who worked at Bell Laboratories and Lucent Technologies after receiving his PhD at Cornell . He started his work on manipulation of microparticles with laser light in the late 1960s which resulted in the invention of optical tweezers in 1986. He also pioneered the optical trapping process that eventually was used to manipulate atoms, molecules, and biological cells. The key phenomenon is the radiation pressure of light; this pressure can be dissected down into optical gradient and scattering forces. Arthur has been awarded by Nobel prize 2018 considering his invention of optical tweezers that grab particles, atoms and molecules with their laser beam fingers. Viruses, bacteria and other living cells can be held too, and examined and manipulated without being damaged. Ashkin’s optical tweezers have created entirely new opportunities for observing and controlling the machinery of life.
Mourou at the École Polytechnique near Paris, and Strickland at the University of Waterloo in Ontario, each receive a quarter of the prize for work that paved the way for the shortest, most intense laser beams ever created. Their technique, named chirped pulse amplification, is now used in laser machining and enables doctors to perform millions of corrective laser eye surgeries every year.
Donna Strickland and Gérard Mourou developed a technique called chirped pulse amplification, which makes it possible to generate high-intensity, ultra-short optical pulses. Strickland is only the third woman to win the Nobel Prize in physics, following Marie Curie in 1903 and Maria Goeppert Mayer in 1963.
“Obviously we need to celebrate women physicists, because we’re out there,” Strickland said in a phone call with the academy after the prize announcement. “And hopefully in time it’ll start to move forward at a faster rate, maybe,”
Strickland and Mourou worked together at the University of Rochester in the 1980s. Mourou was a physics professor who headed a group researching ultra-fast lasers at UR’s Laboratory for Laser Energetics. Strickland studied under him and was the primary author of a scientific paper that first described chirped pulse amplification in 1985.
In announcing the award, the academy described that article as “revolutionary.” It was Strickland’s first scientific publication.
Mourou and Strickland demonstrated what has been described as a stunning advance in laser power, with a table-top terawatt laser. At the time, the peak power of laser pulses was limited because of the serious damage the pulses caused to the material used to amplify them.
The technique that Strickland and Mourou developed takes a short laser pulse, stretches it, amplifies it and squeezes it together again. The breakthrough made it possible to create very precise laser systems. The applications for the technology include Lasik eye surgery, semi-conductor manufacturing, and solid state hard drives.
Strickland received her undergraduate degree in physics from McMaster University in Hamilton Ontario and a Ph.D. in optics from UR in 1989. She currently serves as associate professor and associate chair of the physics department at the University of Waterloo in Ontario, Canada. Mourou, a native of France, came to the University of Rochester after earning his PhD in 1973. He later worked at the University of Michigan, where he was founding director of the Center for Ultrafast Optical Science in 1991. In 2004, Mourou returned to France to become director of the Laboratoire d’ Optique Appliquée at ENSTA-Ecole Polytechnique in Paris.