Sandia National Labs Academic Alliance Collaboration Report 2020-2021
UNM’s Mansoor Sheik-Bahae and other researchers from UNM and Los Alamos National Laboratory used an all-optical refrigeration scheme to successfully cool a photodetector to cryogenic temperatures for the first time. Sheik-Bahae, who performed pioneering work on the physics, measurement, and applications of the cascaded second-order nonlinearities, has made key theoretical and experimental contributions to the field of solid state laser cooling and is working on ultrashort laser pulse characterization, extreme wavelength generation/detection, and semiconductor plasmonics. He is also involved with Sandia’s microelectronics thrust area.
During long deployments, bulky, expensive, and inefficient mechanical refrigerators are used to keep the sensors cool, but their moving parts and gasses cause vibration resulting in blurred images and reduced lifetimes through mechanical wear. Even utilizing significant progress in vibration suppression, microphonic noise becomes a limiting factor in image resolution. In some cases, mechanical refrigerators are switched off to acquire images, an action that carries significant risk of startup failure, and long cool-down times that can approach several days. In this collaborative research project, scientists Seth Melgaard at Sandia and Mansoor Sheik-Bahae at UNM, among others, are working to take the optical refrigeration (OR) technology from academia and build the world’s first optically cooled sensor. OR uses absorption of a laser to generate strong anti-Stokes fluorescence in specific materials and is currently the only cryogenic solid-state cooling technology. It has the ability to achieve the needed temperatures, is vibration free, and could provide low mass, scalable local (i.e., pixel level) cooling. To extend OR beyond the current state-of-the-art, several engineering improvements are needed. By improving size, weight and power through the development of lightweight, compact, efficiently cooled sensors, more missions can accommodate sensor packages. Currently, no solid-state refrigeration is deployed for remote sensing applications. If successful, this technology will benefit a variety of domestic and defense applications. While continuing work on the sensor demo, the team is searching for sponsor follow-on funding with the hopes of realizing a demo in space, perhaps on a small cube satellite. Another LDRD proposal in development is focused on demonstrating a unique aspect of photon recycling, which will further enhance efficiency.
2020-2021 Collaboration Report
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