Sub-threshold operated lead salt lasers for calibration of IR-astronomy detectors

High sensitivity infrared detectors made from extrinsic semiconductors are used for astronomical applications on satellite missions in the earth orbit and for airborne astronomy. High energy radiation reduces the sensitivity and changes the calibration of these photoconductors drastically. On board annealing and frequent recalibration therefore is necessary. Mid infrared diode lasers with low power dissipation can be applied for both purposes. In this paper we focus on the use of Mesa- and Buried-Heterostructure lasers operated below threshold as calibration sources. Data on stability with respect to thermal cycling, mechanical vibrations, and on long term stability of the spontaneous emission are presented.