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Aiming at applications with short integration times of 5 ms and below, necessary for fast moving objects and for cameras where sub-pixel spatial resolution is achieved by microscan methods, we have also developed QWIP FP As with hi~h quantum efficiency (HQE), where we use a higher carrier concentration of 4x10" em-electrons per quantum well (rather than lx10 11 cm-2 as used in the "standard" photoconductive QWIP). In these HQE QWIP FP As, we achieve an increase of the internal quantum efficiency 17 to about 17 = 30 - 40%, which accordingly improves the signal-to-noise ratio at short integration times. This advantage comes at the penalty that slightly lower (by a few Kelvin) detector temperatures are necessary in order to maintain background-limited operation.