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.

Date of Patent:
Feb. 28, 2017

Filed:

Feb. 26, 2016
Applicant:

Sei Optifrontier Co., Ltd., Yokohama-shi, Kanagawa, JP;

Inventors:

Fumiya Uehara, Kanagawa, JP;

Toshiyuki Miyamoto, Kanagawa, JP;

Tetsufumi Tsuzaki, Kanagawa, JP;

Assignee:

SEI OPTIFRONTIER CO., LTD., Yokohama-shi, Kanagawa, JP;

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01S 3/13 (2006.01); H01S 3/09 (2006.01); H04B 10/29 (2013.01); H04B 10/293 (2013.01); H01S 3/091 (2006.01); H01S 3/131 (2006.01); H04B 10/25 (2013.01);
U.S. Cl.
CPC ...
H01S 3/1305 (2013.01); H01S 3/0912 (2013.01); H01S 3/1306 (2013.01); H01S 3/1312 (2013.01); H04B 10/2931 (2013.01);
Abstract

The present embodiment relates to an optical amplifier which can perform an amplification operation equivalent to a normal operation even with an increase of dark current in a PD forming a part of a light detection circuit for monitoring signal light as an amplification object. In the optical amplifier, a detection controller performs an anomaly determination on a light detection circuit due to an increase of dark current in the PD based on a difference between temporal change amounts of a signal component of a voltage of output signal from a light receiving unit including the PD, and a voltage component in a high frequency region included in the signal component. An amplification controller can perform suitable switching of control on a drive current to a pumping light source, based on the result of the determination.


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