An Integrated InGaAs PIN and Bolometer Focal Plane Array for Combined Thermal Imaging and Covert Three Dimensional Imaging

Sensors Unlimited, Inc. will develop and deliver a two-color camera featuring simultaneous, coplanar imaging in both the short-wave infrared (SWIR, 0.9 mm - 1.7 mm) and long-wave infrared (LWIR, 8 mm -12 mm) wavelength bands. The camera's focal plane array will combine detection of both spectral regions in the same uncooled monolithic imager with a single readout integrated circuit for snapshot acquisition of all pixels. Each pixel will contain two detectors: an indium gallium arsenide photodiode for SWIR and a microbolometer for LWIR. The integration of the two detector types will be accomplished by fabricating both on the same indium phosphide substrate. This innovation will simplify existing system designs for image fusion by combining the imagers in the same optical plane. To identify the target objects, the same imager can detect reflected light in the SWIR band and use the thermal band for temperature signatures. In addition, the high-speed performance of InGaAs photodiodes enables future enhancement with LADAR. Our unique SWIR/LWIR 128x128x2 element camera will be the final product of Phase III. In Phase I, we will demonstrate a combined single-element SWIR/LWIR detector. In Phase II, we will demonstrate a 16x16x2 combined SWIR/LWIR focal plane array.