HEL System Designed for Land, Sea, and Airborne Platforms

SAN DIEGO – 8 April 2015 – General Atomics Aeronautical Systems, Inc. (GA-ASI), a leading manufacturer of Remotely Piloted Aircraft (RPA) systems, radars, and electro-optic and related mission systems solutions, today announced that an independent measurement team contracted by the U.S. Government has completed beam quality and power measurements of GA-ASI’s Gen 3 High Energy Laser System (HEL) using the Joint Technology Office (JTO) Government Diagnostic System (GDS).

“These measurements confirm the exceptional beam quality of the Gen 3 HEL, the next-generation leader in electrically-pumped lasers,” said Claudio Pereida, executive vice president, Mission Systems, GA-ASI.

The new laser represents the third generation of technology originally developed under the High Energy Liquid Laser Area Defense System (HELLADS, Gen 1) program. The Gen 3 Laser employs a number of upgrades resulting in improved beam quality, increased electrical to optical efficiency, and reduced size and weight. The recently certified Gen 3 laser assembly is very compact at only 1.3 x 0.4 x 0.5 meters. The system is powered by a compact Lithium-ion battery supply designed to demonstrate a deployable architecture for tactical platforms.

The Gen 3 HEL tested is a unit cell for the Tactical Laser Weapon Module (TLWM) currently under development. Featuring a flexible, deployable architecture, the TLWM is designed for use on land, sea, and airborne platforms and will be available in four versions at the 50, 75, 150, and 300 kilowatt laser output levels.

The GDS was employed by an independent measurement team to evaluate the beam quality of the Gen 3 system over a range of operating power and run time. According to JTO’s Jack Slater, “The system produced the best beam quality from a high energy laser that we have yet measured with the GDS. We were impressed to see that the beam quality remained constant with increasing output power and run-time.”

With run time limited only by the magazine depth of the battery system, beam quality was constant throughout the entire run at greater than 30 seconds. These measurements confirm that the exceptional beam quality of this new generation of electrically-pumped lasers is maintained above the 50 kilowatt level.

Following this evaluation, the independent team will use the GDS again to conduct beam quality measurements of the GA-ASI HELLADS Demonstrator Laser Weapon System (DLWS). The HELLADS DLWS includes a 150 kilowatt class laser with integrated power and thermal management.

HELLADS

While fashions in high-energy lasers have changed as technology progresses, from gas to diode and now fiber, General Atomics Aeronautical Systems (GA-ASI) has stayed its course over more than a decade and believes its third generation of electric laser weapon is ready for prime time.

The company has responded to an Office of Naval Research (ONR) solicitation for a 150-kw laser weapon suitable for installation on DDG-51-class destroyers to counter unmanned aircraft and small boats using only ship power and cooling.

Under ONR’s Solid-State Laser Technology Maturation program, the weapon is to be demonstrated in 2018 on the USS Paul Foster, a decommissioned Spruance-class destroyer that now serves as the U.S. Navy’s ship-defense test vessel at Port Hueneme in California.

GA-ASI has proposed its Gen 3 High-Energy Laser (HEL) system, which recently completed independent beam-quality and power testing for the U.S. government. The Gen 3 system is the third generation of electrically pumped laser using the architecture developed for Darpa’s Hellads program.

Gen 3 has increased electrical-to-optical efficiency, improved beam quality and further reduced size and weight, says GA-ASI. A mockup of the Tactical Laser Weapon Module was displayed for the first time at the Sea-Air-Space show on April 13-15 in Washington.

The module includes high-power-density lithium-ion batteries, liquid cooling for the laser and batteries, one or more laser unit cells and optics to clean up and stabilize the beam before it enters the platform-specific beam-director telescope, says Davis.

The unit cell is a laser oscillator that produces a single 75-kw beam. Modules can be ganged together to produce a 150- or 300-kw beam. There is no beam-combining, Davis says, as there is in systems that use multiple lower-power fiber lasers.

The Pentagon and several other manufacturers have shifted focus to fiber lasers because they are a commercial technology and have higher electrical-to-optical “wallplug” efficiency than diode lasers previously demonstrated at power levels exceeding 100 kw.

But the Gen 3’s efficiency is at the level of fiber lasers, Davis says, adding that the company has worked for several years to improve beam quality and achieved “excellent quality” in the latest tests. Adaptive optics adjust the beam to compensate for atmospheric distortion.

In the independent unit-cell tests, beam quality was measured over a range of operating power and run time, which is limited only by the “magazine depth” of the battery system. “Beam quality was constant throughout the entire run of greater than 30 sec.,” says GA-ASI.

“Fiber lasers are interesting, but it is a matter of maturity,” says Davis. “We are where fiber may be in five years. We have built several versions of this laser over the last 10 years, and we believe [the Gen 3 system] is affordable as is.”

In addition to the ONR program, GA-ASI is eyeing the U.S. Army’s Boeing High Energy Laser Mobile Demonstrator (HEL MD). Live-fire tests of the HEL MD used a 10-kw industrial fiber laser and the Army intends to upgrade the system to a 60-kw Lockheed Martin fiber laser.

The next step is a 120-kw laser, planned for testing in the early 2020s, and for which GA-ASI plans to propose the Gen 3 system. The Air Force Research Laboratory, meanwhile, is interested in a podded laser weapon, although there is no formal program yet.

Davis says the Gen 3’s size enables an airborne laser module in the 150-kw range to be carried by GA-ASI’s Avenger unmanned aircraft. The UAV has sufficient onboard power to recharge the module’s batteries in flight. “That’s the utility; you don’t need to go back to reload,” Davis says.