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. 28, 1992
Filed:
Apr. 26, 1991
Toru Matsuura, Kanagawa, JP;
Shiro Nishi, Tokyo, JP;
Shigekuni Sasaki, Saitama, JP;
Toshihiro Ichino, Kanagawa, JP;
Fumio Yamamoto, Ibaraki, JP;
Shinji Ando, Tokyo, JP;
Fusao Shimokawa, Saitama, JP;
Shinji Koike, Tokyo, JP;
Nippon Telegraph and Telephone Corporation, Tokyo, JP;
Abstract
An optical waveguide which has properties including low optical losses, facile fabrication, controllable core-cladding refractive index ratio, and a high heat resistance is provided. The optical waveguide for light transmission therethrough has a core made of a polyimide obtained from at least one tetracarboxylic acid dianhydride and at least one diamine. The polyimide is (a) a polyimide homopolymer derived from a diamine represented by formula [I] as follows: ##STR1## (b) a polyimide copolymer derived from at least one diamine including the diamine represented by the formula [I]; or (c) a mixture of the polyimide homopolymers.