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. 12, 1990
Filed:
Jun. 27, 1988
Kazuhito Tajima, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
In a wavelength multiplexed optical transmission system, digital signals of separate channels are respectively converted into optical signals of different wavelengths which are assigned to plural optical channels and multiplexed into a beam optical signal for coupling to an optical transmitted medium. Each of the optical channels includes a semiconductor laser for emitting a laser beam and an optical phase or frequency modulator for modulating the laser beam with one of the digital input signals. A light intensity limiter, or a laser diode saturable light amplifier is located in the path of the light from the modulator to maintain the modulated laser beam at a constant amplitude to prevent interchannel crosstalk which would otherwise occur in the transmission medium as a result of variations in the output of the laser and/or modulator.