Theoretical and experimental investigations of infrared hyperspectral imaging systems based on the BIB detectors

BIB detectors are highly favored in the hyperspectral detection domain due to their high sensitivity, broad spectral response, low dark current, and strong radiation resistance. An infrared hyperspectral imaging system based on BIB detectors is under development , applicable in the fields of target detection and imaging. The system includes high-sensitivity linear BIB detectors, high-resolution grating spectrometers, and a cryogenic system. The design of the spectrometer incorporates an off-axis three-mirror system and a segmentable three-channel grating. And the cryogenic system with a dual-temperature zone is employed to provide cooling for the detector and the spectrometer to reduce background radiation noise and to enhance performance, respectively. Additionally, the spot diagrams and the Modulation Transfer Function (MTF) of the spectrometer are analyzed and optimized in different background temperatures. The cooling capacity required by the spectrometer and detector are discussed in different cooling temperatures. In addition, an infrared hyperspectral imaging system integrated with opto-thermal analysis is being developed and tested, and fairly good agreements between the theoretical and experimental results are found. Coupled with a BIB detector with a working spectral range of 6–40μm, a linear array configuration of 64×1, and pixel dimensions of 100 μm×100 μm, the system can reach an MTF value of 0.25. This allows for the capture of clear and discernible images and achieves exceptional imaging quality and spectral resolution capabilities.