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. 18, 1998
Filed:
Apr. 13, 1995
George Anthony Rakuljic, Santa Monica, CA (US);
Victor Leyva, Los Angeles, CA (US);
Amnon Yariv, San Marino, CA (US);
Koichi Sayano, Montebello, CA (US);
Arthur Bruce O'Connor, Redondo Beach, CA (US);
Charles E Tyler, Sunnyvale, CA (US);
Xiaoping Mao, Los Angeles, CA (US);
Harold Everett Miller, Jr, Westminster, CA (US);
Accuwave Corporation, Santa Monica, CA (US);
Abstract
Substantial improvements in photorefractive device lifetimes are provided by control of electron migration which results in the decay of gratings in photorefractive materials due to diffusion and other effects. A new class of photorefractive devices using compensating electronic and ionic gratings having relatively low efficiency but nonetheless usable gratings is provided by arranging the gratings to be reflective in a wavelength band outside the photo-excitation band of the photorefractive material, as by using an infrared operating wavelength. Longer lifetimes in high efficiency gratings are achieved by constant or periodic illumination of photorefractive materials to assure uniform charged distribution of electrons and maintenance of the ionic backbone grating.