Bidirectional Beam Director for Conformal HEL

ABSTRACT: Optical Physics Company (OPC) is proposing to design and prototype a full function beam director suitable for all current phased array control technologies. The proposed beam director significantly simplifies the design of HEL phased arrays by presenting a complete beamlet tracking and steering in an extraordinarily compact design. A full 50 cm diameter beamlet array steerable over a 100 deg cone will have a volume of only 0.037 cubic meters. Given the thickness of the beam steering unit of only a few centimeters, the beam director can transmit out a window only slightly larger than the laser beam itself, even over a 120 degree cone of regard. This window can be curved to match the contour of the aircraft to minimize aerodynamic drag and turbulence. Additional advantages are that the beam director works identically on all polarization states, has an area fill factor around 98%, and eliminates Venetian blinding phase shift between beamlets of up to 14,000 waves/second due to a fast slewing target. The Phase I effort will design and evaluate the beam director in the context of a complete beam control system for an HEL phased array with acquisition, tracking, pointing and steering functions ready for Phase II prototyping. BENEFIT: Tactical and long-range HEL systems are set to transform military operations in all services in the next 10-20 years. Conformal designs, such as those enabled by the proposed bidirectional beam director, promise extremely lightweight, high performance, and cost-effective options for HEL weapons. The target application is a conformal HEL system in a jet fighter. One can also foresee deployment on remotely piloted armed unmanned air vehicles (UAVs). The beam director, beam control and steering methods developed during this project are also applicable to ground based space object imaging, laser rangefinders, as well as commercial aircraft and ship defense. OPC has already demonstrated success with transitioning technologies developed under SBIR funding to ongoing research and acquisition programs. In particular, OPC has become a preferred supplier of deformable mirrors (DM) for high energy lasers. Our endeavor into DM manufacturing is part of a more comprehensive Strategic Plan to take a variety of high end optical system and sub-assemblies that employ our know-how in high precision optics and atmospheric turbulence compensation to market. The beam director we will build under this SBIR project is well aligned with this Strategic Plan. OPC is also well prepared for technology transition having teamed with a prime contractor who is evaluating three phased array architectures with HEL JTO support.