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. 27, 2005
Filed:
Sep. 04, 2003
Takafumi Chiba, Tokyo, JP;
Satoshi Takasugi, Tokyo, JP;
Tetsu Hasegawa, Tokyo, JP;
Hisato Uetsuka, Tokyo, JP;
Takafumi Chiba, Tokyo, JP;
Satoshi Takasugi, Tokyo, JP;
Tetsu Hasegawa, Tokyo, JP;
Hisato Uetsuka, Tokyo, JP;
Hitachi Cable, Ltd., Tokyo, JP;
Abstract
A waveguide type variable optical attenuator has: a substrate; two optical circuits that are in parallel formed on the substrate, each of the optical circuits including two couplers that conduct the branching and coupling of light and are connected to the input port and output port of light and two waveguides through which the two couplers are connected; a polarization maintaining fiber one end of which is connected to the output port of one of the two optical circuits and the other end of which is connected to the input port of the other of the two optical circuits while being twisted 90°; and a heater that is provided around neighboring waveguides of the two optical circuits such that the neighboring waveguides share heat to be generated by the heater.