Mercury cadmium telluride staring arrays for mid-IR detection

Mercury cadmium telluride (CMT or MCT) has for many years been the preferred material for high performance long wave infrared detectors. For mid-IR applications, CMT is also used for many simple photoconductive detectors. The majority of these applications are in instrumentation, industrial process control, thermography or radiometry. CMT is also commonly used for thermal imaging through the 3-5 μm atmospheric window. Advanced detectors for this application are generally two-dimensional `staring´ arrays. GEC-Marconi Infra-Red (GMIRL) specialises in the production of CMT detectors. The paper describes the most advanced 3-5 μm staring array produced, which is a 384×288 element array for the Euclid programme. Designed for use in conjunction with 2×2 optical microscan to produce a full 768×576 TV standard image at 50 Hz field rates, it is capable of resolving scene temperature differences below 20 mK. Special features include the small pixel pitch of 20 μm and the relatively high operating temperature of 120 K. The operating temperature is beyond the capability of competing technologies based on InSb or PtSi