Do not hold powerful laser weapons next to your face

China has claimed to have developed a combat laser rifle. It would have to have a lot of waste heat. 30-40% efficiency is about the maximum. China claims a mass produced cost of $15,000.

If you had a 300-watt laser system without water cooling, then it seems you would be holding something like a 500-watt hot plate while the laser is being fired. I do not think a 300-watt laser would do much damage. More heat would be applied to the face of the soldier shooting the laser rifle since the laser is not over 50% efficient.

The more powerful the laser rifle then the more waste heat will be generated.

Commercial induction heat ranges typically have power settings of 500-3500 watts.

Video of a 200-watt laser built by a Youtuber

China’s laser gun would have a higher quality beam and more efficiency. The higher quality beam means that it would be able to burn material and pop balloons at longer distances. More efficiency would means more of the wattage would go to damage.

Video of Lockheed Martin laser weapon tests

Laser efficiency and power to weight

In 2014, Lockheed built and tested a 30-⁠kW laser that combined the beams of 96 three hundred watt lasers. They then doubled its size. It had 40% efficiency. With that efficiency, a laser system whose beam is at 60 kW generates less than 90 kW of waste heat. Lockheed will try to deliver two 100+ kilowatt lasers by 2020.

The US also has the HEL-JTO (High Energy Laser) that is trying to build a 100-kW laser that occupies about 1.2 cubic meters and could generate more than 150 watts per kilogram, operating at 30 percent efficiency or better. Two of the four projects HEL-JTO launched use fiber laser technology.

Fiber lasers currently reach a maximum of 10 kilowatts of power.

Boeing has a 10 kilowatt system that weighs 300 kilogram. The components include:

* a battery
* a water-cooled chiller
* a commercially available fiber laser
* an upgraded beam director, weighing 40% less than a previous model.

China’s laser rifle is shown being aimed by the person. So it has no beam director.

It does not have a chiller. This would mean that it would be fired and the soldier would have to wait until it was air cooled.

A solid-state laser or fiber laser would need about 3 kilograms to get to 500 watts.

Batteries would be needed.

It would seem that a 3-kilogram system could have a 100-200 watt laser with batteries.
A 6-kilogram system could have 400-500 watt laser with batteries.

It seems like the choice could be made for visual site aiming and to get rid of the beam director. This might make the Boeing system weigh 240 kilograms. Improvements in batteries and lasers could make a Boeing system weight 150-200 kilograms without the beam director. However, it would not be built for $15,000 a piece.

SOURCES- IEEE, Boeing, Lockheed, ArmyTimes, SCMP
Written by Brian Wang