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:
May. 27, 1997
Filed:
Apr. 30, 1996
Ando Electric Co., Ltd., Tokyo, JP;
Nippon Telegraph and Telephone Corporation, Tokyo, JP;
Abstract
The invention offers an optical fiber amplifier with good frequency characteristics which allows the gain to be held constant even without an input signal beam and allows gain control with respect to input optical signals with high-speed power fluctuations. An excitation beam source 8 supplies an excitation beam for light amplification and a control beam source 15 supplies a control beam for controlling the gain to an EDF 4 which amplifies a signal beam by means of optical excitation. An excitation beam monitor 9 measures the power of the excitation beam when inputted to the EDF 4 and an excitation beam monitor 12 measures the power of the excitation beam when outputted from the EDF 4. A comparator 11 calculates the ratio between the power measured by the excitation beam monitor 9 and the power measured by the excitation beam monitor 12. A drive circuit 14 controls the power of the control beam supplied by the control beam source 15 based on the results obtained by the comparator 11.