Improved UV to IR band detector performance through advanced nanostructured antireflection coatings

The performance of optical and imaging systems may be limited considerably by losses due to reflection of signals off substrates and optical components. Nanoengineered optical layers offering tunable refractive index properties provide broadband and omnidirectional suppression of light reflection/scattering with increased optical transmission for enhanced detector and system performance. These nanostructured antireflection (AR) coatings custom designed for specific wavebands from the ultraviolet (UV) to infrared (IR) have many potential optical applications, particularly in maximizing light and IR radiation transmitted onto the surfaces of detectors to increase their sensitivity, for various NASA systems. Through fabrication of these AR nanostructures at various tilt angles of deposition, optimized AR coatings having high laser damage thresholds and reliable in extreme low temperature environments and under launch conditions may be realized. We have developed and advanced such AR nanostructures on GaSb substrates as well as GaSb-based detector devices for 8-14 μm LWIR applications. In this paper we review the latest findings and measurements in the development of these high-performance nanostructure-based AR coatings primarily for advanced LWIR band to NASA Earth Science sensing and imaging applications.