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. 12, 1995
Filed:
Jun. 10, 1994
Katsuyuki Imoto, Sayama, JP;
Hiroyuki Hoshino, Hitachi, JP;
Hitachi Cable, Ltd., Tokyo, JP;
Abstract
An optical waveguide with a specific refractive index difference .DELTA..sub.1 has a constitution in which a core with a high refractive index and having a rectangular section is built in a cladding layer with a low refractive index formed on a substrate. A pig tail optical fiber, formed by a first fiber serially connected to a second fiber, each having a different specific refractive index difference, is connected to an input terminal of the optical waveguide. The second fiber has a specific refractive index difference .DELTA..sub.2 (<.DELTA..sub.1) and is connected to a terminal of the first fiber which has a specific refractive index difference nearly equal to .DELTA..sub.1. A diffusion region in the neighborhood of the connection is formed by diffusing a dopant for refractive index control in the core of the second fiber by heat addition. Due to the diffusion region, the diameters of the first fiber and the second fiber are adjusted so as to be nearly equal.