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:
Sep. 18, 2001
Filed:
Jun. 30, 1999
Applicant:
Inventors:
Shinji Ishikawa, Yokohama, JP;
Toru Iwashima, Yokohama, JP;
Michiko Takushima (nee Harumoto), Yokohama, JP;
Akira Inoue, Yokohama, JP;
Masakazu Shigehara, Yokohama, JP;
Assignee:
Sumitomo Electric Industries, Osaka, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G02B 6/34 ;
U.S. Cl.
CPC ...
G02B 6/34 ;
Abstract
The present invention provides a method for determining a condition of aging for an optical waveguide grating. In this method, the aged deterioration curve of the optical waveguide grating is set as a form of C·t,, where t represents time, and &agr; and C represent parameters. Then, the condition of the aging is determined based on the aged deterioration curve.