Military Laser Hits Battlefield Strength

[via Wired.com]

Huge news for real-life ray guns: Electric lasers have hit battlefield strength for the first time -- paving the way for energy weapons to go to war.

In recent test-blasts, Pentagon-researchers at Northrop Grumman managed to get its 105 kilowatts of power out of their laser -- past the "100kW threshold [that] has been viewed traditionally as a proof of principle for 'weapons grade' power levels for high-energy lasers," Northrop's vice president of directed energy systems, Dan Wildt, said in a statement.

That much power won't get you a Star Wars-style blaster. But it should be more than enough to zap the mortars and rockets that insurgents have used to pound American bases in Iraq and Afghanistan.

The battlefield-strength breakthrough is just one part in a larger military push to finally make laser weapons a reality, after decades of unfulfilled promises. The Army recently gave Boeing a $36 million contract to build a laser-equipped truck. Raytheon is set to start test-firing a mortar-zapper of its own. Darpa is funding a 150 kilowatt laser project that is meant to be fitted onto "tactical aircraft."

Does that mean energy weapons are a done deal? Hardly. There are still all sorts of technical issues -- thermal management and miniaturization, to name two -- that have to be handled first. Then, the ray gunners have to find the money. The National Academies figure it'll take another $100 million to get battlefield lasers right.

Still, clearing the 100 kilowatt hurdle is a big deal. For the longest time, the military research community concentrated on developing chemical-powered lasers. The ray guns produced massively powerful laser blasts. But the noxious stuff needed to produce all that power makes the weapons all-but-impractical in a war zone. (One ray gun took as many as eight shipping containers' worth of chemicals and electronics to power a single blaster.) So the Defense Department shifted gears, and poured money into electric lasers. They're much less hassle to operate. And, given a steady supply of power, they should be able to fire away, almost indefinitely.

At first, these electric lasers were weak. When the military started its Joint High Power Solid State Laser (JHPSSL) program in 2003, these easy-to-maintain lasters could barely produce more than 10 kilowatts of coherent light. Now, Northrop believes, going way past 100 kilowatts should be pretty simple.

In its lab, south of Los Angeles, Northrop combines 32 garnet crystal "modules" into a "laser amplifier chains." Shine light-emitting diodes into 'em, and they start the laser chain-reaction, shooting out as much as 15 kilowatts of focused light. Combine all those beams into one, and you've got yourself a battlefield-strength ray. Northrop's JHPSSL lasers used seven chains to get to 105 kilowatts. But there's room, at least, for an eighth. Which means an even stronger blaster.

The next step is to start trying out the ray gun, outside of the lab. The Army is planning to move the device to its High Energy Laser Systems Test Facility at White Sands Missile Range. Testing is supposed to begin by this time, next year.