A stressed Ge:Ga photoconductor array with three elements applied to the Infrared Telescope in Space satellite was fabricated and tested in experiments at 2.0 K in very low-photon-influx conditions (~ 105 photons/s). Stress was applied to three Ge:Ga detectors in a series by a stable and compact stressing apparatus by using cone-disk springs. The cutoff wavelength was ~ 180 µm. Responsivity was ~ 100 A/W, and the product of quantum efficiency and photoconductive gain, ηG, was ~ 1 with a chopping frequency of 2 Hz. The noise equivalent power was <5 × 10-18 W/Hz½ when low-noise transimpedance amplifiers were used. A slow transient response and a nonlinear response that was dependent on the background photon influx were observed in the experiments. The latter showed that the ηG had a time constant τc that was proportional to Nph-½.
© 1992 Optical Society of America
N. Hiromoto, T. Itabe, H. Shibai, H. Matsuhara, T. Nakagawa, and H. Okuda, "Three-element stressed Ge:Ga photoconductor array for the infrared telescope in space," Appl. Opt. 31, 460-465 (1992)