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:
May. 11, 2004
Filed:
Feb. 04, 2002
Tsutomu Kitoh, Mito, JP;
Yasuyuki Inoue, Mito, JP;
Manabu Oguma, Mito, JP;
Yoshinori Hibino, Mito, JP;
Kaname Jinguji, Mito, JP;
Nippon Telegraph and Telephone Corporation, Tokyo, JP;
Abstract
The present invention provides an optical demultiplexer and an optical multiplexer the transmission characteristics of which are unlikely to be affected by fabrication errors and which have small group delay dispersion. A cross output port (X-OUT) of a second optical demultiplexer element (DEMUX) is selected, and a through output port (T-OUT) of a third DEMUX is selected. A T-OUT of a first DEMUX has a passband equal to the X-OUT of the second DEMUX, and a X-OUT of the first DEMUX has a passband equal to the T-OUT of the third DEMUX. The T-OUT of the first DEMUX has group delay characteristics opposite to those of the X-OUT of the second DEMUX, and the X-OUT of the first DEMUX has group delay characteristics opposite to those of the T-OUT of the third DEMUX.