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A 10-petawatt laser device in Shanghai. With the help of a breakthrough, Chinese scientists hope to fire a laser 10 times that strength within a few years. Photo: Chinese Academy of Sciences

Chinese breakthrough allows physicists to build the world’s most powerful laser

  • Technological leap would allow the firing of a laser 10,000 times more powerful than all the electricity grids in the world combined
  • With this development, the Station of Extreme Light could aid research in new materials, drugs and nuclear fusion energy
Science

A research team in Shanghai has achieved a technological breakthrough to allow them to build the most powerful laser on the planet.

The leap means they could fire a 100-petawatt shot in about two years, a scientist involved in the project told the South China Morning Post on Tuesday.

That single pulse would be 10,000 times more powerful than all the electricity grids in the world combined.

In the incredibly brief but intensive flash of light, humans would witness materials coming from nothing for the first time.

Liu Jun, a member of the Station of Extreme Light (SEL) project with the Shanghai Institute of Optics and Fine Mechanics, said increasing the power of a laser beam was not easy.

A very high energy input could damage optical components such as crystals, lenses and mirrors.

To sidestep the burn issue, scientists would diffract the input beam to a broad spectrum of colours and pump into each colourful beam a relatively small amount of energy that the hardware could tolerate. Then they would compress them back into a single beam, now with its power dramatically amplified.

This compression has been an obstacle for scientists around the world for decades.

“The compressor will burn with so much energy coming in,” Liu said.

In a 19-page paper published in the journal  Optics Express in May, Liu and his colleagues proposed a high-powered laser design that broke the compression procedure into steps, which they said would cut energy intensity to a level safe for the compressor while radically increasing the laser device power output.

This breakthrough has given the SEL facility, which is under construction in Shanghai, a boost, according to Liu.

‘Factory of discoveries’: China aims high to explain the universe

The US$100 million project originally planned to employ four independent laser beams to reach the target power output. But with the new technology, one beam would be enough.

This would reduce the number of some large, critical components, such as diffraction gratings, and cut the cost of the project, said Liu.

“The fewer the beams, the simpler the device. The simpler the device, the more easily it can be built and run. The quality and stability of laser pulses will improve as well,” he added.

When completed in 2023, the SEL facility could open a portal to a new world of physical discoveries, many physicists believe.

Though the laser beam eventually would be fired up in extremely short pulses – with no risk of a blackout on Earth – experts believe it would tear apart space-time for a brief moment to allow scientists to glimpse new physical phenomena that for now only exist in theories.

Einstein’s famous equation E=mc2, for instance, explains that a small amount of matter can be converted to an enormous amount of energy. The atomic bomb proved it. But no one has shown how – or whether – it works the other way round.

The extremely powerful laser beam, when focused on an extremely small spot in a vacuum, can make a subatomic particle pop out of the blue, according to the prediction of physical theory. The SEL was designed to make this happen.

Chinese laser can spot hidden objects from over a kilometre away

But the use of the facility will not be limited to satisfying physicists’ curiosity. It could aid research in a wide range of areas, from new materials and drugs to nuclear fusion energy.

A laser scientist with the Institute of Physics at the Chinese Academy of Sciences in Beijing, said the new Shanghai laser facility would strengthen China’s leading position in the high-power laser race.

Some research teams in Russia, Europe and the United States have proposed similar projects, but none has received sufficient funding from their government, said the physicist who was not involved in the project and requested not to be named because he was not authorised to speak to the media.

“China will almost certainly win,” he said.

The current laser record is 10 petawatts using several beams. Producing a single laser beam 10 times as powerful is an ambitious goal. The design by the Shanghai team was like no others, the unnamed physicist said.

So there would be more challenges ahead, he said, adding that similar large-scale research infrastructure projects built in China had a good record for meeting deadlines, nonetheless. He said many physicists in the world were tracking the Shanghai project.

“Even competitors wish for their success,” he said.

This article appeared in the South China Morning Post print edition as: Breakthrough lights way to most powerful laser
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