BFF-55 Nobel-winning laser discoveries that lit up the field

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NOBEL-PHYSICS-LASERS

Nobel-winning laser discoveries that lit up the field

PARIS, Oct 2, 2018 (BSS/AFP) – Three scientists shared the 2018 Nobel
Physics Prize on Tuesday for their work that has “revolutionised” the field
of laser physics.

Here is a brief explanation of their breakthroughs and how the discoveries
can be applied:

– Optical tweezers –

American physicist Arthur Ashkin was given one half of the prestigious
award for inventing “optical tweezers” — intense laser beams that can grab
microscopic particles and move them about for study.

They use light to move physical objects, “an old dream of science
fiction,” according to the Royal Swedish Academy of Sciences.

The beams use light’s natural radiation pressure, allowing scientists to
examine and manipulate viruses, bacteria and other living cells — even
individual atoms — without damaging them.

The Nobel prize committee said the innovation, which Ashkin developed in
the 1970s and 1980s, had created “new opportunities for observing and
controlling the machinery of life”.

– Optical pulses –

The other half of Tuesday’s prize pot was split between Frenchman Gerard
Mourou and Donna Strickland of Canada, for their joint development of ultra-
short optical pulses.

When early lasers were being developed in the 1960s, scientists
encountered the problem of how to scale up the beams without also boosting
their intensity to potentially dangerous levels.

Mourou and Strickland developed a technique, known as chirped-pulse
amplification (CPA), which enabled researchers to boost laser power but
keeping the intensity safe by having incredibly short light bursts.

CPA first stretches laser pulses over time to reduce their intensity,
before amplifying them and compressing them again.

The compressed pulses saw more light packed into a shorter time,
increasing the intensity of the pulse.

It enables beams to cut or drill holes in various materials, including
living matter, with extreme precision.

Today the technique is used in millions of laser eye surgeries across the
world and is being applied to research in several fields, including cancer
care.

BSS/AFP/FI/ 1656 hrs