Abstract: A light detector (10) comprising a detector cell (12); a system for focusing light (14, 16, 18) on the cell; a liquid crystal (22) positioned in the light path; the liquid crystal (22) being prepared so that it passes light along the light path in the normal operating range of the detector cell (12) and directs light away from the light path when a threshold intensity of light is reached; and source of bias (24) across the crystal to enhance the recovery of the crystal (22).

Abstract: A visible-to-infrared image converter system (10) utilizes a source of infrared light (15), a polarizing beam splitter (19) for separating the infrared light into two polarized beams having their polarity at ninety degrees to one another, and first and second image converters (12, 13) positioned at right angles to one another, each to receive one of the two polarized beams. A source of identical visible information (21) furnishes information to each of the image converters (12, 13) which modulate the infrared beams and reflect them for recombination by the polarizing beam splitter (19).