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. 06, 2000
Filed:
Aug. 05, 1998
Toru Iwashima, Yokohama, JP;
Michiko Harumoto, Yokohama, JP;
Sumitomo Electric Industries, Ltd., Osaka, JP;
Abstract
In an optical filter formed with a grating whose refractive index fluctuates along an optical axis of an optical waveguide so as to reflect light in a predetermined wavelength band, assuming that a position in the grating area is defined by a positional coordinate value z which is standardized by -.pi. to .pi. in a light propagating direction, an amplitude .DELTA.n of refractive index changing width in z satisfies: ##EQU1## by use of predetermined parameters x.sub.1 and x.sub.2 and proportional constants k.sub.1 and k.sub.2, .DELTA.n monotonously increasing or decreasing depending on whether the expression -.pi..ltoreq.z.ltoreq.0 or 0.ltoreq.z.ltoreq..pi. is satisfied, respectively.