Measurement of Reciprocity Failure in Near-Infrared Detectors

Flux-dependent nonlinearity (reciprocity failure) in HgCdTe near-infrared detectors can severely impact an instrument's performance, in particular, with respect to precision photometric measurements. The cause of this effect is presently not understood. To investigate reciprocity failure, a dedicated test system was built. For flux levels between 1 and 50,000 photons s(-1), a sensitivity to reciprocity failure of approximately 0.1% decade(-1) was achieved. A wavelength-independent nonlinearity due to reciprocity failure of about 0.35% decade(-1) was measured in a 1.7 mu m HgCdTe detector.