Hindustan Times (Amritsar)

PHYSICS NOBEL GOES TO LASER RESEARCH TRIO

DISCOVERIE­S THAT WON THE PRIZE

- Agence FrancePres­se letters@hindustant­ims.com

STOCKHOLM: Three researcher­s on Tuesday shared the 2018 Nobel Physics Prize for inventions in the field of laser physics which have paved the way for advanced precision instrument­s used in corrective eye surgery and industry, the jury said.

Arthur Ashkin of the United States won one half of the nine million Swedish kronor (about $1.01 million or 870,000 euros) prize, while Gerard Mourou of France and Donna Strickland of Canada shared the other half.

Ashkin, 96, was honoured for his invention of “optical tweezers” that grab particles, atoms, viruses and other living cells with their laser beam fingers.

With this he was able to use the radiation pressure of light to move physical objects, “an old dream of science fiction,” the Royal Swedish Academy of Sciences said.

Mourou, 74, and Strickland -only the third woman to win the Physics Prize -- won for together developing a method to generate ultra-short optical pulses, “the shortest and most intense laser pulses ever created by mankind,” the jury said. Their technique is now used in corrective eye surgery.

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.

 ?? TWITTER ?? ■ Arthur Ashkin, Gerard Mourou, Donna Strickland
TWITTER ■ Arthur Ashkin, Gerard Mourou, Donna Strickland

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