High-Flux Receiver Optics for Safe Power Beaming

Optical power beaming systems have the potential to revolutionize energy supply for airborne military platforms, allowing networks of unmanned aircraft to operate aloft indefinitely.  To ensure safe and efficient optical power transfer, receiving optics must be designed to provide rigorous photon containment.  Stray reflections and scattered light must be minimized in order to ensure safety for personnel in the vicinity of the systems.   In this program, Glint will develop optical designs for the high-flux receivers with an emphasis on strict control of reflected and scattered light.  The optical designs make use of a novel technology already under development by Glint for producing high-performance polarization-independent antireflective surfaces for injection-molded optics.  The surfaces utilize a dense array of sub-wavelength protrusions to produce an effective graded index, a biomimicry approach known as “motheye” antireflective surfaces that has been extensively studied in recent years. Optimized motheye surfaces have extremely low reflectivity values and better broad-spectrum and wide-angle antireflective properties than provided by conventional vacuum-deposited technologies.  Further, such antireflective surfaces can operate at very high flux without damage because they do not involve interfaces between dissimilar materials.  Glint’s proprietary technology embeds a nanostructured pattern into the mold used to fabricate optical parts, resulting in molded optics with inherent motheye properties.  The approach is unique in allowing motheye surfaces to be produced on curved and faceted surfaces, and also substantially reduces the cost of implementing motheye antireflectivity in optics.   In Phase I, Glint and NMC will develop optimized antireflective surfaces for optical power beaming and will test their performance and durability under high-flux operation.  They will also develop complete optical receiver designs and evaluate their projected performance in optical efficiency and stray light suppression.