(12) United States Patent ao) Patent No.: Us 7,068,897 B2
Russell et al. (45) Date of Patent: Jun. 27,2006
(54) METHOD FOR RESTORING OR
INCREASING PHOTOSENSITIVITY IN
HYDROGEN OR DEUTERIUM LOADED
LARGE DIAMETER OPTICAL WAVEGUIDE
(75) Inventors: Jerin J. Russell, Ellington, CT (US);
Martin A. Putnam, Cheshire, CT (US);
Jay W. Dawson, Livermore, CA (US);
Trevor W. MacDougall, Simsbury, CT
(US); John R. Troll, Baltimore, MD
(73) Assignee: CiDRA Corporation, Wallingford, CT
( * ) Notice: Subject to any disclaimer, the term of this patent is extended or adjusted under 35 U.S.C. 154(b) by 121 days.
(21) Appl. No.: 10/459,653
(22) Filed: Jun. 10, 2003
(65) Prior Publication Data
US 2004/0037504 Al Feb. 26, 2004
Related U.S. Application Data
(60) Provisional application No. 60/387,798, filed on Jun. 10, 2002.
(51) Int. CI.
G02B 6/02 (2006.01)
(52) U.S. CI 385/123; 385/37
(58) Field of Classification Search 385/123 126
See application file for complete search history.
The present invention provides a new and unique method for increasing the photosensitivity of a large diameter optical waveguide having a cross-section of at least about 0.3 millimeters. The method features loading the large diameter optical waveguide with a photosensitizing gas at a pressure at least about 4000 pounds per square inch (PSI) at a temperature of at least about 250E Celsius. The photosensitizing gas may be hydrogen, Deuterium or other suitable gas. The method also includes the step of using a particular large diameter optical waveguide having a diameter of greater than 0.9 millimeters. The method may be used as part of a process for writing a Bragg grating in an inner core or a cladding of the large diameter optical waveguide.
11 Claims, 3 Drawing Sheets