The Future of Lasers: Approaching the Exawatt Scale
by Catherine Meyers
Imagine a laser so powerful that it can break down a vacuum and make particle-antiparticle pairs pop into existence. This technology sounds like science fiction, but is now on the horizon according to Gérard Mourou of the École Polytechnique in France, who gave the second of two plenary talks on Tuesday morning.
The first laser was built in 1960, but the technology soon hit a power plateau because light above a certain intensity would destroy the gain medium. Mourou is one of the inventors of a technique called chirped pulse amplification, or CPA, which can overcome this barrier by stretching a laser pulse into a longer, lower-power form, then amplifying the stretched pulse before compressing it again. The end result is an extremely short but super powerful laser pulse.
CPA, along with other advances, enabled the current petawatt lasers, which can be found in more than a dozen labs around the world. The machines are capable of creating laser beams with orders of magnitude more power than the total power output of every power station in the world, Mourou said. But even higher power on the exawatt scale is possible, Mourou said, by taking a single-cycle petawatt pulse and further compressing it so that it lasts mere zeptoseconds.
Such short and powerful pulses could in theory accelerate protons to relativistic speeds over centimeters, essentially recreating the LHC -- the 27-kilometer-long particle accelerator under the Swiss-French border -- in a space the size of a dime. They could transmute nuclear waste into less hazardous materials, produce protons for medical treatments, and even help simulate a black hole.
These advances represent a quantum leap for technology, Peter Delfyett, the LS General Co-Chair, said in closing remarks at the plenary. Or, as Mourou summarized it, “the best is yet to come.”
Posted: 19 Sep 2018 by Catherine Meyers