: The Architecture for Diode High Energy Laser Systems (ADHELS) program will develop all-solid-state laser diode drivers with integrated fault mode protection that will decrease the size and weight of these laser systems by a factor of four by allowing the laser diode array to operate at elevated temperature, increase the diode array lifetime tenfold, and decrease lifecycle costs fivefold.
DARPA's Architecture for Diode High Energy Laser Systems (ADHELS) is dedicated to investigating new wavelength laser beam-combining architectures to produce a new generation of compact high-efficiency, high-energy laser (HEL) systems. Such an architecture complements current programs developing airborne-based, megawatt-class chemical lasers and ground-based, multihundred kilowatt-class solid-state slab lasers by providing a new class of HELs with record-low size, weight and waste power that can be integrated onto tactical air vehicles.
ADHELS aims to develop a technology to produce high-power, high-brightness laser beams in an architecture readily scalable to power levels of military interest by combining the output high-power, high-efficiency, single-mode lasers into a single high-brightness beam. ADHELS addresses laser beam-combining efficiency with the added challenge of maintaining high beam quality and low beam divergence expected for tactical applications.
The program is structured as a 36-month, two-phase effort to develop efficient laser beam-combining approaches for high energy laser systems. While the first phase of research explored both coherent and spectral beam combining, the program’s second phase is focused solely on the spectral beam combining of high-power, high-efficiency, single-mode lasers. The goal at the end of this program is demonstration of a near-diffraction-limited system architecture, operating at laser wavelengths corresponding to efficient atmospheric transmission, and readily scalable to a 100-kilowatt class HEL system. The resulting technology is applicable to any branch of the Military Services and is expected to be developed for industrial and military applications. One near-term application of interest is to spectrally combine high power fiber lasers to defend unmanned aerial vehicles against man-portable air-defense systems.