China's military claims to have found a way to build a laser weapon that can fire indefinitely

• Armies around the world are testing high-energy laser weapons to intercept targets.
• If successful, the weapons could change warfare, as they travel near the speed of light.

Chinese scientists claim they have found a way to build a laser weapon that can be fired indefinitely, which would dramatically increase its effectiveness over other laser weapons.

If their claims are true, it means that China has leapfrogged over the US in developing high-energy laser weapons that could be used on the battlefield.

The capability China's military scientists claim to have developed, however, has not yet been seen in action.

Researchers at the National University of Defense Technology, a military-research institution in Hunan, said they developed a cooling system that allowed high-energy lasers to remain powered up without getting too hot, the South China Morning Post reported.

The system is a "huge breakthrough in improving the performance of high-energy laser systems," the scientists said in a paper published in Acta Optica Sinica, a Chinese-language peer-reviewed journal, on August 4, the South China Morning Post reported.

"High-quality beams can be produced not only in the first second but also maintained indefinitely," they added.

Laser beams can heat up gas in the air, which can reduce the quality of the beam and cause damage inside the laser chamber, the report said. To bypass this issue, the scientists said, they developed a system that could blow clean gas through the chamber and remove waste heat.

This allowed them to make the laser more compact and efficient, the South China Morning Post said.

"So far, many advanced designs and research progress on dynamic air-blowing thermal management in China have not been reported," the scientists said, the South China Morning Post reported. "This is the first time that some of the designs and test results [have gone] to the public," they said.

China and the US, among other nations, are looking to develop combat-ready high-energy laser weapons that can generate beams strong enough to melt steel.

High-powered laser weapons have the potential to be a game-changing technology for warfare and defense because they could shoot targets such as drones, missiles, and small aircraft at nearly the speed of light at lower costs than interceptor missiles. A challenge, though, has been cooldown time.

In a tweet about the reports, Steve Weaver, a former British military official, said that if the news on the achievement by the Chinese scientists was true, it would put China ahead of the US in more ways than one.

"This is a big breakthrough considering the US failures in this area," he said, highlighting a section of the South China Morning Post report pointing to US military systems that didn't quite meet expectations.

Major defense companies in the US have also been pushing forward the development of laser-based weapons as part of projects including the US Department of Defense's High Energy Laser Scaling Initiative. The beams could be used to defend sites from incoming threats.

The US military has in recent years embraced these systems.

The Army, for example, has mounted 50-kilowatt lasers on its Stryker armored fighting vehicles, while the Navy's amphibious warship USS Portland, building on earlier testing, has tested a 150-kilowatt laser against a surface target. The Marines have tested a Compact Laser Weapons System in the range of 2 to 10 kilowatts, and the Air Force has received high-energy laser pods for its fighter jets.

Lockheed Martin announced last year it had delivered a 300-kilowatt laser to the Defense Department. It's now working on a more powerful, 500-kilowatt laser, the company's website says.

While there has been renewed interest in this technology, there are major limitations to its use.

Laser weapons are usually less powerful the farther away they are from the target and can be foiled by bad weather such as fog and storms, which can reduce the beam's range and quality, the US Government Accountability Office said, adding that cooling requirements could also limit their effectiveness.