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:
Sep. 28, 2004
Filed:
May. 21, 2002
Terukazu Naruse, Kawasaki, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
An optical multiplexer/demultiplexer having a small-loss structure that uses an arrayed waveguide grating to optimally make the passband characteristic of demultiplexed light flat. An optical input waveguide and a sector slab waveguide are connected by a directional coupler. The directional coupler comprises a central waveguide including an end portion on the output side of the optical input waveguide and arranged waveguides which are arranged on both sides of the central waveguide and the exits of which are connected to the sector slab waveguide. A taper is formed on both side portions of the central waveguide so that the width of a core will gradually narrow in the direction of the exit, and the central waveguide is located so that this end portion will not touch the sector slab waveguide. The width of a core in each of the arranged waveguides is uniform. The arranged waveguides are arranged on both sides of the central waveguide by the same numbers so that the arranged waveguides will be parallel to the taper formed on the central waveguide. As a result, light from the central waveguide couples with the arranged waveguides.