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:
Sep. 24, 2002
Filed:
Sep. 01, 2000
Haruo Nakaji, Yokohama, JP;
Motoki Kakui, Yokohama, JP;
Sumitomo Electric Industries, Ltd., Osaka, JP;
Abstract
The present invention relates to an optical amplifier comprising a structure which prevents transmission quality from lowering and enables constant gain control with a higher speed and higher accuracy. In a typical embodiment of the present invention, amplified light from an EDF is once guided to an optical filter by way of an optical circulator. Of thus guided amplified light, noise light passes through the optical filter, whereas each of signal components is reflected thereby, so as to separate the noise light and signal components from each other. The noise light having passed through the optical filter is detected by a photodetector, and gain control is carried out by a gain control circuit so as to suppress fluctuations in the detected noise light power.