By David Hambling, technology expert
Ever since lasers were invented in 1960, enthusiasts have talked of turning them into death rays able to zap missiles out of the sky, melt tanks and blow up warships.
Despite these promises, military lasers have been decidedly low-powered, in the form of rangefinders, illuminators, target designators and dazzlers. The compact, high-energy laser was always just out of reach - until now.
The latest generation of lasers are based on efficient solid-state electronics.The most common type are fibre lasers, in which several industrial lasers are bundled together and combine their output.
This merged the power of six five-kilowatt lasers into a single 30-kilowatt beam.
A big limitation of laser weapons is the amount of power it takes to destroy a target.
The LaWS beam was effective against ”low-end asymmetric threats” – specifically, it could shoot down small drones, and damage small powerboats, at a range of about a mile.
A cannon the same size can shoot down full-size aircraft and destroy larger boats at longer ranges.
The advantage of lasers is their precision and the fact that they strike at the speed of light, hitting high-speed manoeuvring targets impossible for a cannon.
The cost per shot is minimal - less than a pound per zap for even the most powerful - and the magazine lasts is bottomless. Given a power supply, a laser can shoot down incoming missiles all day and never run out of ammunition.
These advantages are driving planners to start fielding lasers now, with the aim of steadily upgrading them over time to take on ever-harder targets at ever-increasing ranges.
The US Navy is one of the leaders. HELIOS, the successor to LaWS, is under development by Lockheed Martin.
This will start at 60 kilowatts when it is fielded on a new destroyer in 2020, but may later be increased to 150 kilowatts and beyond.
Other US developments include a 5-kilowatt ground-based laser in a Stryker armoured vehicle, and a proposed defensive weapon for aircraft known as SHiELD (Self-protect High-Energy Laser Demonstrator) capable of taking out missiles.
Missile manufacturer MBDA is developing a laser called Dragonfire for the UK Ministry of Defence. This is a beam-combining weapon and is described as “50-kilowatt class.”
The first test firing of Dragonfire should take place this summer and the prototype is due to be delivered in 2019.
Deployment may be in the early 2020s, for short-range air defence and protection against mortar, artillery and rockets.
Other nations are also busy in this area. German company Rheinmetall has developed a series of mobile high-energy fibre lasers, the largest being a 50-kilowatt version which fits into a shipping container, and the company is now working on a 120-kilowatt laser.
This could be integrated with their existing radar-guided Skyshield system enabling it to engage air threats with cannon, missile or laser fire as appropriate. Again, this is likely to be happening in the 2020s.
Technology analysts at Technavio have predicted that China would surpass the US high-energy laser research and development by 2022.
News media recently latched on to claims by a Chinese company to have built a ‘laser AK-47’, a portable directed-energy assault weapon.
Video of the weapon in action, as well as basic physics, indicate that this is a fairly low-powered device, only able to burn someone if they stand still for long enough.
The Chinese also have more serious lasers, including the Silent Hunter, with claimed output of “at least 50-70 kilowatts”, which provided protection for the 2016 G20 summit at Guangzhou.
Silent Hunter can be carried by a heavy truck and is claimed to be able to cut through 5mm-thick steel from a kilometre away. A version of the system is already being offered for export.
There is still plenty of hype about lasers, and their actual battlefield effectiveness remains to be seen.
In particular, their ability to cope with smoke and dust, and to stay locked on to real-world targets is unproven.
However, their rapidly increasing power and the rate at which they are being fielded suggest that the day of the laser weapon has finally arrived.