Space mid-IR detectors from DRS

Abstract

The Blocked Impurity Band (BIB) detector was invented in the early 1980's and subsequently developed by our team. The original arsenic-doped silicon (Si:As) detectors addressed the need for low-noise, radiation-tolerant, mid-IR detectors for defense surveillance from space. We have since developed large-format BIB focal plane arrays to address high-background requirements of ground-based telescopes and missile interceptors, low-background requirements of the Space Infrared Telescope Facility (SIRTF), and very low background requirements of the mid-IR instruments for the Next Generation Space Telescope (NGST) and Terrestrial Planet Finder. Most of these applications employ Si:As BIB detectors, but antimony-doped silicon (Si:Sb) BIB detectors are used for some SIRTF bands. Other demonstrated types including phosphorus (Si:P) and gallium-doped (Si:Ga) BIB detectors may have application niches. We have proposed development of a BIB detector type utilizing both Si:As and Si:P layers to optimize dark current vs. wavelength performance. Wavelength response for silicon BIB detectors extend to a maximum of ~40 microns (Si:Sb), but we have also demonstrated germanium BIB detectors for wavelengths extending to several hundred microns. We are currently developing germanium BIB detector arrays for astrophysics applications, including space telescopes beyond NGST.