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:
Mar. 24, 1992
Filed:
Apr. 24, 1990
Takao Matsumoto, Yokohama, JP;
Masafumi Koga, Yokosuka, JP;
Nippon Telegraph & Telephone Corporation, Tokyo, JP;
Abstract
An optical wavelength demultiplexer including an optical conversion device which converts a difference in wavelengths of a plurality of input signals into a difference in spatial power distribution of the input light signals, and a pattern recognition element for recognizing patterns of the spatial power distribution and taking out output signals. At the output portion of the optical conversion device, spatial power distributions are formed which are different for different wavelengths. After converting the spatial power distributions by the pattern recognition element into electrical signals, pattern recognition of the signals is performed to regenerate the original input signals with their respective wavelengths. The optical conversion device uses a diffractive grating or a combination of an optical multimode circuit, an optical multimode fiber, and a plurality of optical wavelengths. The pattern recognition element is constructed by a combination of a photo-detector array and a neural network, or a combination of a hologram element, a photo-detector array and a neural network.