Adaptive Thermal Infrared Band ROIC for Planetary Science Missions

Electro-Optical and Infrared (EO/IR) detectors sensing in the 400nm to 13 micron waveband are extensively employed in planetary science space instruments. These detectors can be divided into two distinctive subgroups, namely the visible through shortwave infrared (SWIR) band detectors (400nm ndash; 2500nm), and the mid-wave infrared (MWIR ndash; 3um to 5um) and long-wave infrared (LWIR 8um ndash; 13um) thermal bands detectors. Each of these two categories requires a readout integrated circuit (ROIC) optimized for the specific subgroup to efficiently multiplex and readout the photocurrent from the photodiodes.nbsp;nbsp;The first ROIC type optimized for shorter wavelength bands needs to have the following characteristics:Smaller pixel pitch (near 10um) optimized for Nyquist spatial sensing of shorter wavelengths.High gain (smaller well size) to provide good SNR for low flux sensing since these bands have lower irradiance and typically use a narrower bandwidth filter.nbsp;The second ROIC type optimized for longer thermal wavelength bands needs to have the following characteristics:Larger pixel pitch (near 20-25um) to match the blur spot size for Nyquist sampling of longer wavelengths.Lower gain (large well size) to provide good SNR for high flux sensing since these bands have higher irradiance and typically use a wider bandwidth filter.There is an established need to develop a novel ROIC for thermal bands being used for planetary science. Our team has extensive space mission experience to provide NASA with an optimal solution. The proposed ROIC will provide the desired high well capacity, a high frame rate, a large format, space qualifiable design, while simultaneously keeping the cold space power very low.nbsp;Such as ROIC will be suitablenbsp;nbsp;for all typical detector types used for these bands, such as (but not limited to) quantum well IR photodetectors (QWIP), HgCdTe (MCT), and strained-layer superlattices (SLS).nbsp;