The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 27, 1991
Filed:
Jun. 08, 1989
Joseph Lindmayer, Potomac, MD (US);
Quantex Corporation, Rockville, MD (US);
Abstract
A photoluminescent material used for detection of infrared light is prepared using a base material, first and second dopants, a carbonate of the base material, and a fusible salt. The base material is an alkaline earth metal sulfide such as calcium sulfide. Calcium carbonate is used to decrease phosphorescence after charging, whereas lithium fluoride is used to allow the material to be fused together. Samarium oxide and europium oxide are used as the first and second dopants for establishing a communication band and an electron trapping level, respectively. The photoluminescent material is made according to a process involving drying the material, heating the material in a graphite crucible to a fusing temperature in a dry inert atmosphere, grinding the material after cooling, and reheating the material to below the fusing temperature, but sufficiently high to repair the crystal surfaces. The material is then placed in a transparent binder and applied to a substrate. Alternatively, thin film techniques may be used to apply the material to a substrate to realize a device with fine optical resolution.