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:
Jul. 01, 2003
Filed:
Aug. 24, 2000
Oleg M. Efimov, Orlando, FL (US);
Leonid B. Glebov, Orlando, FL (US);
Vadim I. Smirnov, Orlando, FL (US);
Larissa Glebova, Orlando, FL (US);
University of Central Florida, Orlando, FL (US);
Abstract
A novel process is proposed for the volume diffractive element (Bragg grating) fabrication in photosensitive silicate glasses doped with silver, cerium, fluorine, and bromine. The process employs a photo-thermo-refractive (PTR) glass of high purity exposed to ultraviolet (UV) radiation of a He—Cd laser at 325 nm followed by thermal development at temperatures from 480° C. to 580° C., preferably at 520° C., from several minutes to several hours. Absolute diffraction efficiency up to 95% was observed for 1 mm thick gratings. Maximum spatial frequency recorded in PTR glass was about of 10,000 mm . No decreasing of diffraction efficiency were detected at low spatial frequencies. Original glasses were transparent (absorption coefficient less than 1 cm ) from 350 to 4100 nm. Induced losses in exposed and developed glass decreased from 0.3 to 0.03 cm between 400 and 700 nm, respectively, and did not exceed 0.01-0.02 cm in the infrared (IR) region from 700 to 2500 nm.