Large Aperture Micro-Electro-Mechanical Modulating Retro-Reflector

This project is to manufacture Modulating Retroreflectors (MRR) that combine microelectromechanical system (MEMS) modulators into one or more facets of a corner-cube retroreflector. The modulating element will be a mirror that has the characteristic that when unenergized it will retroreflect incident light in the zero-order (specular) mode, and when energized by an externally applied voltage it will deform via electrostatic actuation into a corrugated shape that diffracts light into a first-order mode, spoiling retroreflection. Contrast in the return signal is produced by switching between these two states to encode binary information. The work builds on a previously supported NAVWAR effort that demonstrated feasibility of many of the essential components and assembly processes for this type of MRR. The proposed effort logically derives and concludes from those prior technological innovations, and will lead to MRRs usable by NAVWAR in test beds for space-based asymmetric FSO communication links. Outcomes of the proposed project have high potential to yield new commercial products with benefits to both government and private sectors.