Thermo-Electric Superlattice Focal Plane Array (TESFPA)

Thermo-Electric Superlattice Focal Plan Array (TESFPA) is a new uncooled IR sensor for imaging in broad infrared spectrum (from 3 to 14 microns) achieved using nano-engineered superlattice thermoelectric materials. TESFPA is designed to meet DARPA goals for achieving higher sensitivity and faster response time than the current uncooled microbolometers, and to enable multispectral/polraimetric capability. Microbolometer is an absolute temperature sensor with limitation for performance improvement due to its extreme material sensitivity to temperature and thermo-resistive detection technique. In contrast, TESFPA detector is a true differential sensor with high temperature stability and material uniformity, because it uses thermo-voltaic detection. Analysis has shown that TESFPA detector technology is 100 times less sensitive to changes in ambient temperature than the microbolometer. By using thermo-voltaic detection and nano-engineered materials such as the superlattice thermoelectric systems, TESFPA can now achieve sensitivity approaching that of the cooled HgCdTe photon detectors. More importantly, TESFPA will dramatically reduce the amount of the post processing electronics required, thereby reducing system power consumption and size, each by an order of magnitude as compared to microbolometers. Successful development of TESFPA will enable future development of the IR Camera-in-a-Chip, making IR cameras in sizes similar to visible cameras that are ubiquitous today.