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:
Apr. 09, 1991
Filed:
Apr. 17, 1990
Tatsuro Kunikane, Yokohama, JP;
Takashi Yokota, Yamato, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
A wavelength-division multiplexing optical transmission system is disclosed which transmits light of wavelengths .lambda..sub.1, .lambda..sub.2 and .lambda..sub.3 (.lambda..sub.1 <.lambda..sub.2 <.lambda..sub.3) by way of a single optical fiber. An optical multiplexer/demultiplexer of the filter type is used which includes a parallelogram prism, a first filter formed on a side face of the parallelogram prism, and second and third filters formed on the opposite side face of the parallelogram. Bidirectional optical fiber communications between the central telephone exchange side and a subscriber side can be achieved using such optical multiplexer/demultiplexer of the filter type. With the arrangement of the invention, an optical multiplexer/demultiplexer of the filter type can be produced at a low cost without the necessity of using a filter having a wide stopping band as a filter to be formed on a parallelogram prism.