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:
Dec. 08, 1998
Filed:
Aug. 29, 1996
Hisato Uetsuka, Ibaraki-ken, JP;
Hideaki Arai, Ibaraki-ken, JP;
Hitachi Cable, Ltd., Tokyo, JP;
Abstract
A width of a core in an optical waveguide is decreased in accordance with a value of a predetermined equation, as a distance of a position of the core to the center position thereof is decreased. Consequently, a rectangular spectrum property having no ripple is obtained on a lower wavelength side in a reflection grating. In addition, the width of the core is changed at the position Z in the direction of light propagation, while a UV light is radiated to the core, so that a periodically striated distribution of refractive indices having an envelope which is changed in accordance with a value of '.vertline.sin(C.multidot.Z).vertline./.vertline.C.multidot.Z.vertline.' is formed in the core of the optical waveguide, and a phase of a light to be propagated in the direction of the light propagation is shifted at the position Z as defined below by .pi..