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:
Oct. 07, 2003
Filed:
Feb. 15, 2001
Applicant:
Inventors:
Assignee:
Hitachi Cable, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G02B 6/28 ; G02B 6/26 ; G02B 6/42 ;
U.S. Cl.
CPC ...
G02B 6/28 ; G02B 6/26 ; G02B 6/42 ;
Abstract
In the optical multiplexer/demultiplexer according to the invention, an MMI (multi mode interference) coupler having a percentage coupling of about 50% is used as first and second optical couplers, and a directional coupler having a percentage coupling of less than 10% is used as third and fourth optical couplers. By virtue of this constitution, the optical multiplexer/demultiplexer according to the invention has a small dependency upon wavelength and can be used in a wide waveband, is less susceptible to a preparation error, and, at the same time, has good wavelength flatness in passband and a wide rejection band.