First woman physics Nobel winner in 55 years
DISCOVERIES THAT WON THE PRIZE
NEWDELHI: A woman has won the Nobel Prize in Physics after 55 years, and only the third time in its history, as three scientists shared the prestigious award on Tuesday for inventions that have “revolutionised laser physics”.
Canada’s Donna Strickland, 59, joined elite scientists Marie Curie, who won the Nobel in 1903 for her work on radioactivity, and Maria Goeppert-mayer, who got it in 1963 for her discoveries about nuclear structure.
Strickland shared this year’s prize with Arthur Ashkin of the US and Gerard Mourou, 74, from France, who were recognised for their work in advancing optical laser technology. At the age of 96, Ashkin is the oldest Nobel laureate. Ashkin was awarded half the nine million Swedish kronor cash prize for making science fiction reality with his “optical tweezers”, which use highly focused laser beams to create an attractive and repulsive force that can be used to hold, turn and move microscopic objects such as bacteria or living cells without damaging them.
The device uses the difference in the refractive index (ratio of light in vacuum to the ratio in a particular medium) to physically hold particles as small as a micron (one millionth of a metre).
One year after developing it in 1986, Ashkin and Joseph M Dziedzic demonstrated the use of the tweezers in biological sciences by trapping individual virus and bacterium. Ashkin’s work was the basis for American physicist Steven Chu’s work on cooling and trapping atoms, which earned him the 1997 Nobel Prize for Physics.
“Advanced precision instruments are opening up unexplored areas of research and a multitude of industrial and medical applications,” the award’s organisers tweeted. The tweezers ability to manipulate viruses and living cells without damaging them have provided scientists an opportunity to study biological processes such as molecular motors responsible for movement in the cellular world, DNA, and the inner life of cells.
The other half of the prize money was shared by Strickland and Mourou for developing the “the shortest and most intense laser pulses ever created by mankind”. Their technique, known as “chirped pulse amplification (CPA)”, uses short laser pulses, stretches them in time, amplifies them and squeezes them together again to create intense pulses that can precisely cut through or drill into materials and living tissue.
The technique also helps keep the peak power of the laser pulse low enough to not experience detrimental effects such as distortion of the optical pulse or destruction of the medium of laser amplification. CPA, developed in the mid-1980s, is the technology behind all the highest power lasers.