Scientists from the UK and South Korea may have found a new technique that could help ramp up the power of scientific lasers by a million times or more.
Scientists from the UK and South Korea have discovered a way
to create laser pulses 1,000 times stronger than currently possible. Using
computer simulations, they have discovered that a new way of compressing the
light can drastically increase its intensity to such an extent that it can
extract particles from a vacuum. This new technique could open up doors for
important discoveries into the very nature of matter.
Uncover the nature of matter
Researchers from the University of Strathclyde, Ulsan
National Institute of Science & Technology (UNIST), and Gwangju Institute
of Science and Technology (GIST) have proposed a simple idea to revolutionize
the next generation of lasers. They suggest using the gradient in the density
of plasma, which is fully ionized matter, to cause photons to bunch together.
This is similar to the way a group of cars bunches up as they encounter a steep
hill. If this technique is successful, it could increase the power of lasers by
more than one million times from what is currently achievable.
The most powerful lasers in the world have a peak power of
approximately ten petawatts. A new 20 petawatt laser called the "Vulcan
20-20" is currently under construction at STFC Rutherford Appleton
Laboratory. To put this into perspective, the earth's upper atmosphere receives
173 petawatts (173 x 10^15 W) of sunshine, about one-third of which reaches
Earth's surface. A petawatt is equivalent to 10^15 watts, an exawatt is
equivalent to 10^18 watts, and a zettawatt is equivalent to 10^21 watts. The
sun produces 4 x 10^26 watts of power, equal to 400,000 zettawatts.
“An important and fundamental question is what happens when
light intensities exceed levels that are common on earth. High-power lasers
allow scientists to answer basic questions on the nature of matter and the
vacuum and explore what is known as the intensity frontier," explained
Professor Dino Jaroszynski of the University of Strathclyde’s Department of
Physics.
“Applying terawatt to petawatt lasers to matter has enabled
the development of next-generation laser-plasma accelerators, which are thousands
of times smaller than conventional accelerators. Providing new tools for
scientists is transforming the way science is done. We have set up the Scottish
Centre for the Application of Plasma-based Accelerator (SCAPA) at the
University of Strathclyde to push applications based on high-power lasers
forward," he added.
The new laser amplifying technique will help physicists
explore some fundamental aspects of interest, from the so-called
"intensity frontier" to being able to extract particles from a vacuum.
The research has applications in astrophysics by simulating stellar phenomena
and addressing energy issues through laser fusion research. It could also prove
helpful in pushing our understanding of the Schwinger limit. This is a
theoretical point where light can be converted into matter, with immense
theoretical and practical implications.
Professor Min Sip Hur of UNIST added that “the results of
this research are expected to be applicable in various fields, including
advanced theoretical physics and astrophysics. It can also be used in laser
fusion research to help address the energy issues facing humanity. Our combined
Korean and UK teams plan to experimentally test the ideas in the lab.”
“Plasma can perform a role similar to traditional
diffraction gratings in CPA systems but is a material that cannot be damaged.
It will, therefore, enhance traditional CPA technology by including a very
simple add-on.” He added, “Even with plasma of a few centimeters in size, it
can be used for lasers with peak powers exceeding an exawatt," said
Professor Hyyong Suk of GIST.
Discover the universe's secret
"Understanding the nature of matter and vacuum at intensities above 1024 W/cm2 are among the outstanding challenges of modern physics. High-power lasers also enable the study of the astrophysical phenomena in the laboratory, providing unique glimpses into the interior of stars and the [universe's origin]," explains Strathclyde University.