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:
Apr. 10, 2007
Filed:
Dec. 30, 2003
Shinji Ishikawa, Yokohama, JP;
Toshiki Taru, Yokohama, JP;
Masakazu Shigehara, Yokohama, JP;
Masaki Ohmura, Yokohama, JP;
Shinji Ishikawa, Yokohama, JP;
Toshiki Taru, Yokohama, JP;
Masakazu Shigehara, Yokohama, JP;
Masaki Ohmura, Yokohama, JP;
Sumitomo Electric Industries, Ltd., Osaka, JP;
Abstract
The present invention relates to an optical fiber having a structure which allows further improvements to be made both in terms of lower reflectance and narrower bandwidth, and to a fiber grating type filter including the optical fiber. The optical fiber applied to the fiber grating type filter comprises a core region extending along a predetermined axis, and a cladding region provided on an outer periphery of the core region. The core region does not contain any photosensitive dopant which contributes to predetermined wavelength light photosensitivity as a glass property, but a part of the cladding region contain such a photosensitive dopant. By means of this composition, it is possible to form a grating, which has a grating plane slanted by a predetermined angle with respect to the optical axis, in a part of the cladding region surrounding the core region.