Solid-state light valve

Recent developments in the solid-state light valve promise a high-quality projection display. The heart of the solid-state light valve is a cathode-ray tube which operates with a modulated and scanning write beam depositing charge on an electrooptic crystal target. The charge pattern on the target causes optical changes which result in modulation of an external light source. The tube incorporates an erase flood gun to control persistence of the display. This paper discusses an unique reflected light configuration with the target operating at reduced temperature and illustrates the resulting image performance. Accomplishments of contracts with Isomet Corporation on crystal targets of KD2P (potassium dideuterium phosphate) and with EDO, Ltd., on isomorphs of KDP (potassium dihydrogen phosphate) are included. Work being performed by the National Bureau of Standards on crystal perfection and electrode interaction is also presented. The paper concludes with a brief summary of various applications of the solid-state light valve concept, and a short synopsis of results obtained by others that support our enthusiasm for the device.