Improved Two-Wavelength Focal-Plane Array of QWIPs

A focal-plane array (FPA) of GaAs-based quantum-well infrared photodetectors (QWIPs) that would detect images in two wavelength bands simultaneously is undergoing development. From ratios between image intensities at the two wavelengths, one can calculate the temperatures of imaged objects by use of Planck's radiation law. In several respects, this device is similar to the one described in "Two-Wavelength Focal-Plane Array of QWIPs" (NPO-19658) NASA Tech Briefs, Vol. 22, No. 1 (January 1998), page 8a. Both devices are intended to serve as prototypes of multispectral imaging devices for a variety of scientific, industrial, and military infrared instruments.