Scalable Beamed Energy Laser Concentrator

Oxford Defense North Carolina and the Lubin Lab of the University of California, Santa Barbara will develop a diffractive optical element (DOE) for concentration and homogenization of laser beamed energy, as would be delivered to the lunar surface from orbiting transmitters. When compared to an unconcentrated solar array, concentrating optical flux on smaller photovoltaic (PV) cells from an estimated beam of 180 W/m2 to 10 kW/m2 spots significantly increases electrical power, reduces mass, and provides higher quality heat for thermal storage. The use of flat optics enables optimization for wide acceptance angles with techniques such as afocal optics. Reducing or eliminating tracking mechanisms further reduces mass and moving parts, and enables rovers where an orientation cannot be guaranteed. The Phase I effort will produce an optical design and select a scalable fabrication technology to meter-scale DOE arrays, which may include replication/roll-to-roll nano-imprinting technology. In developing a fabrication plan, both polymer and glass DOEs will be considered. A polymer DOE can provide a solution to lunar dust accumulation by rolling and exposing a new section when transmission is impaired. There is a broad range of markets beyond the lunar power beaming, including concentrators for terrestrial PV systems, and meter-scale apertures for free-space optical communication and remote sensing.