The 2018 Nobel Prize in Physics has been awarded to three scientists involved in laser physics. One half of the prize was given to Arthur Ashkin for his role in developing optical tweezers, which use the radiation pressure of light to move microscopic objects. The other half was awarded jointly to Gérard Mourou and Donna Strickland, for designing a method to generate high-intensity, ultra-short laser pulses.
When the laser was first invented in the 1960s, it was kind of a solution searching for a problem. But over time, scientists began to understand the usefulness of having such a concentrated source of light at their disposal. One such scientist was Ashkin, who realized that the radiation pressure of light could theoretically be harnessed to manipulate physical objects on the microscopic scale, such as particles and atoms. The optical tweezers were born.
In 1987, those tweezers were used to hold and study living bacteria without harming them, signaling another major breakthrough. Over the decades since, these "tools made of light" have been put to work probing the mysteries of the microscopic world, allowed scientists to witness "Brownian motion" (which Einstein thought would be impossible) and may be paving the way towards tractor beam technology in the future.
For their part, Mourou and Strickland invented a way to create ultra-short, high-intensity laser pulses. The technique, known as chirped pulse amplification (CPA), involves stretching the laser pulses out over time to flatten out the peak power, before amplifying them and compressing them again. That packs more light into a smaller space, increasing the intensity of the pulses.
These incredibly fast and intense laser pulses have since been developed to the point where we can use them to study events that happen on time scales as small as attoseconds – quintillionths of a second. They may have applications in laser cutting, medical procedures, spintronics, particle accelerators, and 3D holograms.
The announcement of this year's Nobel Prize in Physics follows from yesterday's reveal of the Physiology or Medicine prize, which was awarded to James P. Allison and Tasuku Honjo for research in cancer immunotherapy. Other prizes are due to be awarded through the rest of the week.
In the video below Mats Larsson, a member of the Nobel Committee for Physics, explains the significance of the prize-winners' research.
Source: Nobel Prize
