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:
Jun. 15, 2010
Filed:
Mar. 24, 2005
Susumu Noda, Kyoto, JP;
Takashi Asano, Kyoto, JP;
Seiichi Takayama, Chuo-ku, JP;
Kyoto University, Kyoto, JP;
TDK Corporation, Tokyo, JP;
Abstract
The present invention has been made for providing a photonic crystal capable of multiplexing or demultiplexing light within a wavelength band having a certain width. It includes a slab-shaped bodyprovided with plural forbidden band zonesandand holesandhaving different sizes are arranged in the forbidden band zones with different cycles, respectively. Also formed are a trunk waveguideextending along the direction inclined by +30 degrees from a perpendicular of the boundarybetween the forbidden band zonesandand a branch waveguideextending along the direction inclined by −30 degrees. A ray of light within the multiplexed/demultiplexed wavelength band, which is excluded from the transmission wavelength band of the trunk waveguidein the forbidden band zoneand included in the transmission wavelength band of the trunk waveguidein the forbidden band zoneis reflected by the boundaryand thereby demultiplexed from the trunk waveguideinto the branch waveguide. Thus, all the rays of light whose wavelengths are within the multiplexed/demultiplexed wavelength band having a certain width are demultiplexed into the branch waveguide. Therefore, even if the wavelength of the optical signal is deviated due to some error, the light can be demultiplexed. This is also true for the multiplexing operation.