Reciprocity Failure in HgCdTe Detectors: Measurements and Mitigation

TL;DR

This study investigates reciprocity failure in HgCdTe near-infrared detectors, revealing its characteristics, variability, and mitigation through cooling, with implications for improving detector performance in astronomical applications.

Contribution

It provides the first detailed measurements of reciprocity failure in HgCdTe detectors and demonstrates effective mitigation by cooling to 110 K.

Findings

Reciprocity failure sensitivity is about 0.1% per decade.

Cooling detectors to 110 K reduces reciprocity failure to negligible levels.

Large differences in reciprocity failure are observed across different detector production runs.

Abstract

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.