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:
Jun. 26, 2001
Filed:
Jun. 09, 1999
Michiko Harumoto, Kanagawa, JP;
Masakazu Shigehara, Kanagawa, JP;
Sumitomo Electric Industries, Ltd., Osaka, JP;
Abstract
The present invention relates to an optical filter having a long-period grating which couples, in signal light propagating through a core region, core mode light having a predetermined wavelength to cladding mode light, thereby attenuating the core mode light; and a method of making the same. In particular, in the filter area provided with the long-period grating, the intervals of individual parts exhibiting its average refractive index is constant along the advancing direction of the signal light, whereas values of maximum points and minimum points of a refractive index modulation function defining the refractive index vary along the advancing direction of the signal light.