The powerful laser can be used to examine phenomena believed to be responsible for high-power cosmic rays, which have energies of more than a quadrillion (10¹⁵) electronvolts (eV). Although scientists know that these rays originate from somewhere outside our solar system, how they are made and what is forming them has been a longstanding mystery.

"This high intensity laser will allow us to examine astrophysical phenomena such as electron-photon and photon-photon scattering in the lab," said Chang Hee Nam, director of CoReLS and professor at Gwangju Institute of Science & Technology. "We can use it to experimentally test and access theoretical ideas, some of which were first proposed almost a century ago."

In Optica, the researchers report the results of years of work to increase the intensity of laser pulses from the CoReLS laser. Studying laser matter-interactions requires a tightly focused laser beam and the researchers were able to focus the laser pulses to a spot size of just over one micron, less than one fiftieth the diameter of a human hair. The new record-breaking laser intensity is comparable to focusing all the light reaching earth from the sun to a spot of 10 microns.