Researchers call on industry to develop high-energy sources for laser weapons that shoot down unmanned aircraft
ARLINGTON, Va. – US military researchers are calling on industry to develop affordable high-energy laser sources for future laser weapons that can destroy or disable enemy unmanned aerial vehicles (UAVs).
Officials at the US Defense Advanced Research Projects Agency (DARPA) in Arlington, Virginia, issued a general announcement (HR001122S0017) late last month for the Modular Efficient Laser Technology (MELT) program.
MELT seeks to develop a compact, scalable, actively combined and coherent beam solid state laser source with excellent beam quality to create a scalable low size, weight and power (SWaP) laser source that can be mass produced.
MELT aims to capitalize on technologies such as semiconductor fabrication techniques, coherent beam combining, photonic integration, and 3D integration and packaging.
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Today’s laser weapons that use multiple beam-combined high-power fiber amplifiers as high-energy laser sources, as well as large, complex optical subsystems that condition and project the laser beam don’t scale well, according to DARPA researchers.
On the other hand, coherent beam combined tiled array high energy laser sources are scalable because they eliminate these large subsystems.
Coherent-beam combined mosaic arrays provide a pathway to better high-energy laser sources due to the ability to generate and project the laser beam directly without bulk optics; the intrinsic scalability of a tiled table without inherent limits; the ability to perform non-mechanical beam steering for beam jitter corrections; and the ability to apply complex phase corrections to compensate for atmospheric disturbances.
The proliferation of small, low-cost unmanned aerial vehicles (UAVs) on the battlefield requires a layered defense that includes low-cost laser weapons. Laser weapon deep loaders are suitable for countering hostile drone swarms and have the potential to achieve very low operating costs – assuming low production costs can be achieved. Counter-UAVs and similar applications require a wide range of power levels from kilowatts to megawatts, which is not possible today.
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Instead, MELT seeks to develop a laser slab as the building block for compact, scalable, panel-mounted laser weapons. Laser tiles will fit into planar arrays for upgradeable laser weapons with performance comparable to or better than current laser weapons.
MELT seeks to demonstrate a 3 by 3 laser panel array with excellent beam quality as a scalable high energy laser source.
Mass, volume and size targets for laser tiles and panel laser tile array include solid state amplifier transmitters, optics, phase detection and control, power supply, power conversion, heat dissipation, computing, external connections, electricity between tiles, coolant and data connections.
Each MELT tile will contain a 2D array of laser emitters whose phase can be continuously detected and controlled to achieve a coherent beam combination. For scalable power output, several to several hundred of these tiles can be arranged as a panel-mounted gimbal-mounted laser weapon source that produces a usable output beam.
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The DARPA MELT project presents three technical challenges: a dense planar mosaic amplifier array with uniform spacing and 2D surface-normal emission; realizing a scalable phase detection architecture for a panel high energy laser source; and the realization of a compact and scalable cooling solution to remove the anticipated thermal load of a panel high energy laser source.
The MELT program will be a five-year, $60 million program. All proposals in response to this BAA must address all three phases.
The objective of this program is to develop a scalable, low SWaP laser source that can be mass produced. This will require the development of a new type of high energy laser source. The MELT program is only interested in laser technologies based on semiconductor diodes that do not include optically pumped brightness converters.
Interested companies should upload abstracts by March 7, 2022 and full proposals by May 2, 2022 to the DARPA BAA website at https://baa.darpa.mil.
Email your questions or concerns to Thomas Ehrenreich, DARPA MELT Program Manager, at [email protected] More information is online at https://sam.gov/opp/11dc6b43a8ef4723ae5e004c29537c99/view.