Cryogenic Optical Refrigeration for Space Applications

ABSTRACT: If awarded a SBIR Phase II contract, ThermoDynamic Films, LLC, together with the University of New Mexico (UNM) will build a first-generation optical cryocooler. They will add a calibrated load to the device and characterize its efficiency and its cooling speed. Solid-state cryocoolers, which are compact and produce no vibrations, are ideal for many space-born and terrestrial electronics and sensor applications. Currently, the dominant solid-state cooling technology is thermoelectric cooling, which uses the electrical Peltier effect. Despite decades of effort, the lowest achievable temperature for multi-stage thermoelectric coolers (TECs) is around 170 K. The TDF/UNM team is developing an alternative approach to solid-state cooling technology: optical cryocooling. To date, this collaboration has used this technology to cool from room temperature to 93 K with about 1% efficiency. This is the world record cooling for optical refrigeration - or any solid-state cooling technology. BENEFIT: In many areas of national defense, scientific and laboratory analytic instruments, medicine and high performance electronics, it is necessary to cool instruments and devices to cryogenic temperatures (below -150Celsius). Cryocoolers are essential components in the infrared (IR) systems that are used for space-born defense applications such as surveillance and ballistic missile guidance. Cryocoolers are an important part of the U.S. governments priority of heightened homeland and international military security. Cryocoolers are also needed to cool superconductors in a host of medical and geological applications. With no moving parts, the optical cryocoolers being developed by ThermoDynamic Films, LLC would not be subject to wear. Additionally, they do not utilize any fluids, which can leak and generally need replenishing. Additional advantages include the compactness of these refrigerators, total lack of vibrations, agility, high temperature stability, the absence of electromagnetic interference (EMI) and rapid cool down.