Improvements in Operating the Raytheon 320 × 240 Pixel Si:As Impurity Band Conduction Mid‐Infrared Array

Shigeyuki Sako, Y. Okamoto, Hirokazu Kataza, Takashi Miyata, Shinya Takubo, Mitsuhiko Honda, T. Fujiyoshi, Takashi Onaka, Takuya Yamashita

Publications of the Astronomical Society of the Pacific · 2003 · 35 citations · 4 references

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Abstract

We have developed a new operating method for the Raytheon 320 × 240 pixel Si:As IBC detector (hereafter 320 × 240 FPA), the largest mid‐infrared array detector currently available designed for ground‐based astronomy. The array shows quite a strange behavior when a bright source is observed. In images that contain a stellar object sufficiently brighter than the background flux, the signal level of the 320 × 240 FPA drops in the vicinity or along the same row or column of the stellar object. The level‐drop phenomena are caused mainly by transient variations in the characteristics of the source followers in the detector readout circuit (ROIC). We successfully corrected the variations by correlated quadruple sampling, which reduces the level‐drop phenomena appreciably. We evaluated the properties of the ROIC and optimized the bias voltages supplied for the array. The detective quantum efficiency of the 320 × 240 FPA was also estimated.

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