In a paper that made the cover of the journal Applied Physics Letters, an international team of researchers has demonstrated an innovative technique for increasing the intensity of lasers. This approach, based on the compression of light pulses, would make it possible to reach a threshold intensity for a new type of physics that has never been explored before: quantum electrodynamics phenomena.
Researchers Jean-Claude Kieffer of the Institut national de la recherche scientifique (INRS), E. A. Khazanov of the Institute of Applied Physics of the Russian Academy of Sciences and in France Gérard Mourou, Professor Emeritus of the Ecole Polytechnique, who was awarded the Nobel Prize in Physics in 2018, have chosen another direction to achieve a power of around 1023 watts (W). Rather than increasing the energy of the laser, they decrease the pulse duration to only a few femtoseconds. This would keep the system within a reasonable size and keep operating costs down.
To generate the shortest possible pulse, the researchers are exploiting the effects of non-linear optics. “A laser beam is sent through an extremely thin and perfectly homogeneous glass plate. The particular behavior of the wave inside this solid medium broadens the spectrum and allows for a shorter pulse when it is recompressed at the exit of the plate,” explains Jean-Claude Kieffer, co-author of the study published online on 15 June 2020 in the journal Applied Physics Letters.
