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تسجيل مستخدم جديدInvestigating reciprocity failure in 1.7-micron cut-off HgCdTe detectors
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Flux dependent non-linearity (reciprocity failure) in HgCdTe NIR detectors with 1.7 micron cut-off was investigated. A dedicated test station was designed and built to measure reciprocity failure over the full dynamic range of near infrared detectors. For flux levels between 1 and 100,000 photons/sec a limiting sensitivity to reciprocity failure of 0.3%/decade was achieved. First measurements on several engineering grade 1.7 micron cut-off HgCdTe detectors show a wide range of reciprocity failure, from less than 0.5%/decade to about 10%/decade. For at least two of the tested detectors, significant spatial variation in the effect was observed. No indication for wavelength dependency was found. The origin of reciprocity failure is currently not well understood. In this paper we present details of our experimental set-up and show the results of measurements for several detectors.
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A detailed study of reciprocity failure in four 1.7 micron cutoff HgCdTe near-infrared detectors is presented. The sensitivity to reciprocity failure is approximately 0.1%decade over up to five orders of magnitude in illumination intensity. The four
detectors, which represent three successive production runs with modified growth recipes, show large differences in amount and spatial structure of reciprocity failure. Reciprocity failure could be reduced to negligible levels by cooling the detectors to about 110 K. No wavelength dependence was observed. The observed spatial structure appears to be weakly correlated with image persistence.
Flux dependent non-linearity (reciprocity failure) in HgCdTe near infrared detectors can severely impact an instruments performance, in particular with respect to precision photometric measurements. The cause of this effect is presently not understoo
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