American physicist Arthur Ashkin, French physicist Gérard Mourou and Canadian physicist Donna Strickland have won the Nobel prize 2018 in physics.
Arthur Ashkin, who was awarded half the prize, has been given the award for the optical tweezers and their application to biological systems. Laureates Gérard Mourou and Donna Strickland who shares the remaining half, has been awarded Nobel for their method of generating high-intensity, ultra-short optical pulses. Donna Strickland is only the third female physics laureate and the first woman in 55 years to win the prize.
Arthur Ashkin invented optical tweezers that grab
particles, atoms, viruses and other living cells with their
laser beam fingers. This new tool allowed Ashkin to rea-
lise an old dream of science fiction – using the radiation
pressure of light to move physical objects. He succeeded in getting laser light to push small particles towards
the centre of the beam and to hold them there. Optical
tweezers had been invented.
A major breakthrough came in 1987, when Ashkin used
the tweezers to capture living bacteria without harming
them. He immediately began studying biological systems
and optical tweezers are now widely used to investigate the machinery of life.
Gérard Mourou and Donna Strickland paved the way
towards the shortest and most intense laser pulses ever
created by mankind. Their revolutionary article was
published in 1985 and was the foundation of Strickland’s
Using an ingenious approach, they succeeded in creating ultrashort high-intensity laser pulses without destroying
the amplifying material. First they stretched the laser
pulses in time to reduce their peak power, then amplified them, and finally compressed them. If a pulse is compressed in time and becomes shorter, then more light is packed together in the same tiny space – the intensity of the pulse increases dramatically.
Strickland and Mourou’s newly invented technique,
called chirped pulse amplification, CPA, soon became standard for subsequent high-intensity lasers. Its uses include the millions of corrective eye surgeries that are conducted every year using the sharpest of laser beams.
The innumerable areas of application have not yet been completely explored. However, even now these celebrated inventions allow us to rummage around in the microworld in the best spirit of Alfred Nobel – for the greatest benefit to humankind.