InGaAS detectors for miniature infrared instruments

In the past year, there has been substantial impetus for NASA to consider missions that are of relatively low cost as a trade off for a higher new mission launch rate. To maintain low mission cost, these missions will be of short duration and will use smaller launch vehicles (e.g., Pegasus). Consequently, very low volume, very low mass instrument (a.k.a. miniature instrument) payloads will be required. Furthermore, it is anticipated that the number of instruments flown on a particular mission will also be highly constrained; consequently increased instrument capability will also be desired. In the case of infrared instruments, focal planes typically require cooling to ensure high performance of the detectors, especially in the case of spectrometers where high D* is necessary. Since a major portion of an instrument's mass and power budget is consumed by the focal plane cooler, detector technologies that require only modest or no cooling can contribute significantly to the realization of a miniature infrared instrument. InGaAs detectors feature high D*, low dark current, and response not only in the 1 3 jim SWIR regime, but also in the visible regime as well. The latter feature can extend the versatility of a given spectrometer by enabling greater spectral band response while maintaining focal plane simplicity. In this paper, we discuss the InGaAs detector technology and its potential application in miniature infrared instruments.