Far-infrared detector development for space-based Earth observation

DRS Sensors & Targeting Systems with silicon materials partner Lawrence Semiconductor Research Laboratory and development partner NASA Langley Research Center Earth Science Directorate are developing improved far-infrared detectors for Earth energy balance observations from orbit. Our team has succeeded in demonstrating the feasibility of extending the wavelength range of conventional arsenic-doped-silicon Blocked Impurity Band (BIB) detectors (cut-off ~28 µm) into the far infrared. The new far-IR member of the BIB detector family operates at temperatures accessible to existing space-qualified cryocoolers, while retaining the very high values of sensitivity, stability, linearity, and bandwidth typical of the broader class of silicon BIB detectors. The new detector should merit serious consideration for the Climate Absolute Radiance and Refractivity Observatory (CLARREO) mission defined by the recent National Research Council’s Decadal Survey for Earth Science. Proposed further development of this detector technology includes wavelength extension to a goal of at least 100 µm, improvements in detector design, and implementation of light-trapping packaging. These are developments that will enable increased radiometric accuracy, reduced spatial smearing, and simpler calibration approaches for CLARREO.