Characterizing the spatial non-uniformity and temporal stability of QWIP and T2SL cooled infrared detector focal plane arrays

Fixed pattern and temporal noise in infrared Focal Plane Arrays are inherent in the technology and must be corrected to achieve optimal performance in optical gas imaging. These noise sources are intrinsic to the manufacturing process of these devices and the read-out electronics. This paper presents the characteristics of these noise sources for Type 2 Superlattice and Quantum Well Infrared Photodetectors. Experimental results visualise the raw uncorrected non-uniformity of the respective focal plane arrays along with their gain and offset correction tables. The Quantum Well Infrared Photodetector (Sulphur Hexafluoride) shows better uniformity in the uncorrected frames than the Type 2 Superlattice (Volatile Organic Compound), but both detectors show similar performance after correction. The corrected frames are evaluated and a quantity, the absolute median residual per frame, is presented to quantify the residual non-uniformity after correction. Results show that the standard 2-point NUC is effective at correcting the non-uniformity with low levels of remaining noise.