Lauren Fuge
After a decade of work, researchers at the Center for Relativistic Laser Science (CoReLS) at the Institute for Basic Science in South Korea have achieved a record-high laser pulse intensity – over 1023 Watts per centimetres squared (W/cm2).
This is equivalent to focusing all of the light reaching Earth from the Sun onto a spot just 10 microns wide – just a little bigger than the width of a human red blood cell.
It beats the 1022 W/cm2 laser demonstrated by a team at the University of Michigan in 2004.
“This high-intensity laser will let us tackle new and challenging science, especially strong field quantum electrodynamics, which has been mainly dealt with by theoreticians,” says Chang Hee Nam, director of CoReLS and professor at Gwangju Institute of Science & Technology.
As described in a paper published in the journal Optica, this record-breaking result required two things: a laser with an extremely high power output and one that is focused onto a very small spot. More familiar continuous-wave lasers can’t manage much more than megawatt-scale intensity, but higher energies are possible in pulsed laser systems that shoot out energy in quadrillionths of a second.
In 2017, the team previously reported another incredibly powerful laser system, which produced 4 petawatt pulses, equivalent to producing a power 1000 times larger than all the electrical power on Earth but lasting less than 20 femtoseconds (20 quadrillionths of a second).
In this new study, the team focused their petawatt laser onto a spot just over one micron wide – equivalent to less than one-fiftieth of the diameter of a single human hair. To do this, they used an adaptive optics system using deformable mirrors to precisely correct distortions in the laser, reminiscent of the kind of systems used in astronomy. Then, a large off-axis parabolic mirror was used to tightly focus the pulses on the target.
The laser will enable science to examine the complex interactions between light and matter in ways not previously possible. It could even help us understand incredibly energetic (and enigmatic) cosmic phenomena like cosmic rays.
“In addition to helping us better understand astrophysical phenomena, it could also provide the information necessary to develop new sources for a type of radiation treatment that uses high-energy protons to treat cancer,” Nam adds.
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