Wide-angle Non-mechanical Steering Development Using Thin Polarization Gratings

ABSTRACT: A non-mechanical technique for steering the field of view of lidar sensors is being proposed. This coarse steering technique allows the field of view of active sensors to be moved in precise discrete steps. The ability to scan over ±20° in one dimension has been demonstrated. For Phase II, this capability will be extended to two dimensions and implemented as a compact package. The compact, two-dimensional beamsteerer will be integrated with a fine angle steering module that uses two 1x12,288 element optical phased arrays. Using this approach, the modular steering assemblies can be implemented separately or in combination to provide the coverage and accuracy needed for different applications. For example, step and stare imaging lidars would perhaps use only the coarse steering module and satellite laser communications would require both coarse and fine capabilities. The technique proposed for the coarse steering module has the ability to scale to large apertures, handle high energy beams and provide fast response without complicating the system design. The modular beamsteering architecture makes use of liquid crystal assemblies, which are economical to produce. BENEFIT: The ability to non-mechanically point an optical system is important in a variety of applications including free space optical communications, remote sensing and weapon guidance. Non-mechanical systems have the potential to be more accurate, smaller, lighter and less expensive than systems that use gimbals to position the beam. Future deployment of optical systems in small airborne or space-based platforms will eventually require these attributes. "