The Royal Swedish Academy of Science has awarded the 2023 Nobel Prize in Physics to Pierre Agostini, Ferenc Krausz and Anne L'Huillier for work that's "given humanity new tools for exploring the world of electrons inside atoms and molecules."
The award recognizes experiments by the researchers to produce extremely short pulses of light, which can enable rapid processes inside atoms and molecules to be imaged and measured.
While working at a French laboratory in 1987, Anne L'Huillier – now based at Lund University in Sweden – and colleagues demonstrated that when infrared laser light was transmitted through a noble gas, different light overtones (described as "waves that complete a number of entire cycles for each cycle in the original wave") were produced.
"The infrared light caused more and stronger overtones than the laser with shorter wavelengths that had been used in previous experiments," explained the Royal Swedish Academy of Science. L'Huillier continued to look into the effect during the 1990s, with her results laying the groundwork for future breakthroughs.
In 2001, a research group in France led by Pierre Agostini managed to produce a series of consecutive light pulses "together with a delayed part of the original laser pulse, to see how the overtones were in phase with each other." The procedure allowed the duration of the pulses to be measured, with each pulse lasting 250 attoseconds.
An attosecond is one quintillionth of a second – "we can imagine a flash of light being sent from one end of a room to the opposite wall, this takes 10 billion attoseconds." Changes in electrons are said to occur in a few tenths of an attosecond.
At the same time as Agostini and team were working on multiple light pulses, Ferenc Krausz's research group in Austria came up with a technique to isolate a single pulse – which lasted 650 attoseconds – and use it to "track and study a process in which electrons were pulled away from their atoms."
These experiments effectively demonstrated that extremely short bursts of light could be used to study the movements of electrons, and the technology has since advanced to the stage where pulses of just a few dozen attoseconds can be produced.
"We can now open the door to the world of electrons," said Eva Olsson, Chair of the Nobel Committee for Physics. "Attosecond physics gives us the opportunity to understand mechanisms that are governed by electrons. The next step will be utilizing them."
The laureates will receive their awards at special ceremonies on December 10, with the Physics Prize equating to 11 million Swedish kronor (around US$990k) shared equally between them.
Yesterday, the 2023 Nobel Prize in Physiology or Medicine went to Katalin Karikó and Drew Weissman for their contributions to the development of mRNA vaccines against COVID-19. The Chemistry Prize will be announced tomorrow.
Source: Nobel Prize