DARPA asks Northrop Grumman to develop high-power laser weapons technology for counter-uncrewed vehicles
ARLINGTON, Va. – U.S. military researchers needed affordable high-energy laser sources for future laser weapons to destroy or disable enemy unmanned aerial vehicles (UAVs). They found a solution from Northrop Grumman Corp.
Officials of the U.S. Defense Advanced Research Projects Agency (DARPA) in Arlington, Va., announced an $8 million order last Friday to the Northrop Grumman Space Park segment in Redondo Beach, Calif., for the Modular Efficient Laser Technology (MELT) program.
MELT will demonstrate the first compact high-power laser tile as the key building block for next-generation scalable high-energy-laser sources in counter-uncrewed laser weapons.
Semiconductor laser source
Northrop Grumman engineers will develop a compact, scalable, and actively coherently beam combined semiconductor laser source with excellent beam quality to create a mass-producible, low size, weight, and power (SWaP) scalable laser source.
Northrop Grumman seeks to develop enabling technologies in semiconductor manufacturing, photonic integrated circuits, coherent beam-combining algorithms, semiconductor cooling, and optical lithography, and will move these new laser weapons technologies into Army, Air Force, and Navy programs.
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In 2024, the MELT program sought to design thermal management for a semiconductor amplifier planar array; simulate thermal management for electrical-to-optical efficiency; and demonstrate a planar array of emitters in a laboratory.
This year the program seeks to fabricate a full laser tile array of semiconductor amplifiers with good electrical-to-optical efficiency; and design an integrated laser tile with good beam quality.
Technology challenges
Today's laser weapons use fiber laser array high-energy laser sources, complex optical benches, and beam directors, which are large, heavy, contain many separate components, and costly to fabricate and integrate.
MELT will capitalize on recent advances in coherent beam combining and photonic integrated circuit fabrication to develop tiled arrays integrated with semiconductor-based optical systems, low-loss waveguides, optical interconnects, and application-specific integrated circuits (ASICs) into a compact laser tile that can be integrated with a supporting backplane to provide scalable high-energy laser sources.
This will provide a scalable high-energy-laser architecture that maintains excellent beam quality and enables laser weapons deployment on small systems like uncrewed vehicles.
MELT aims to capitalize on technologies such as semiconductor fabrication techniques, coherent beam combining, photonic integration, and 3D integration and packaging.
UAV proliferation
The proliferation of small, low-cost uncrewed aerial vehicles (UAVs) on the battlefield requires a layered defense that includes low-cost laser weapons. The deep magazines of laser weapons are suited to counter swarms of hostile UAVs, and have the potential to achieve very low operating cost -- assuming low production costs can be achieved. Counter-UAV and similar applications need a broad range of power levels from a few kilowatts to megawatts, which isn't possible today.
Instead, MELT seeks to develop a laser tile as the building block for compact, scalable, panelized laser weapons. The laser tiles will integrate into planar arrays for scalable laser weapons with comparable or better performance than current laser weapons.
MELT seeks to demonstrate a 3-by-3 panelized array of laser tiles with excellent beam quality as a scalable high-energy laser source.
The mass, volume, and size goals for the laser tiles and panelized array of laser tiles include the semiconductor amplifier emitters, optics, phase sensing and control, power delivery, power conversion, thermal dissipation, computing, external connections, inter-tile electrical, coolant, and data connections.
Laser tile panels
Each MELT tile will contain a 2D array of laser emitters whose phase can be sensed and controlled continuously to achieve coherent beam combination. For scalable output power, several to several hundred of these tiles may be arranged as a panelized, gimbal-mounted laser weapon source that produces a usable output beam.
The DARPA MELT project has three technical challenges: a dense planar tiled array of amplifiers with uniform spacing and emission normal to the 2D surface; realizing a scalable phase sensing architecture for a panelized high-energy laser source; and realizing a compact scalable cooling solution to remove the anticipated thermal load from a panelized high-energy laser source.
The goal of this program is to develop a mass-producible, low SWaP, scalable laser source. This will require the development of a new type of high-energy laser source. The MELT program is interested only in semiconductor diode-based laser technologies that do not include optically pumped brightness converters.
For more information contact Northrop Grumman Space Park online at www.northropgrumman.com/what-we-do/microelectronics, or DARPA at www.darpa.mil/research/programs/modular-efficient-laser-technology.
John Keller | Editor-in-Chief
John Keller is the Editor-in-Chief, Military & Aerospace Electronics Magazine--provides extensive coverage and analysis of enabling electronics and optoelectronic technologies in military, space and commercial aviation applications. John has been a member of the Military & Aerospace Electronics staff since 1989 and chief editor since 1995.
