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:
Nov. 09, 1976
Filed:
Sep. 25, 1975
Gary Carl Bjorklund, West Windsor, NJ (US);
Linn Frederick Mollenauer, Colts Neck, NJ (US);
Bell Telephone Laboratories, Incorporated, Murray Hill, NJ (US);
Abstract
The disclosed distributed feedback laser employs an alkali halide crystal having a spatially modulated pattern of a stable color center and a complementary spatially modulated pattern of U-centers. The stability of the color centers is provided by initial additive coloration, conversion to U-centers, and subsequent reconversion; and the spatial modulation is provided by patterning the reconversion by exposing a portion of the crystal to an interference pattern of coherent light. Conversion occurs by two-photon absorption. The very large penetration depth and the use of ultraviolet frequencies that are only about one-half of the magnitude of the frequencies that would otherwise be required make this device and process attractive for thick holograms and for distributed feedback devices such as lasers.