Instrument effects in polarized infrared images

Michael R. Descour, MEMBER SPIE University of Arizona Optical Sciences Center Tucson, Arizona 85721 Abstract. We describe three instrument effects that cause polarized infrared images of a blackbody source to exhibit intriguing polarization dependence and image nonuniformity. The origins of these problems are reflection of background radiation from the wire-grid polarizer and frictional heating of the polarizer mount. Our model shows that the two surfaces of a wire-grid polarizer act like a partial polarizer-analyzer pair for reflected radiance. These effects must be considered carefully in applications such as polarimetric remote sensing, which require calibration uncertainties less than 1%.