OPTICAL AMPLIFIER

Japanese Patent JP3258815

B2

PURPOSE: To automatically suppress an abnormal peak light output by automatically adjusting an optical input value switching from a fixed optical output to low gain corresponding to the optical input at the time of normal use.
CONSTITUTION: The part of the input light 20 to an optical amplifier is received by the circuit 2-1 of a light receiving device. As for the converted electric signal, the modulation signal through a low-pass filter 3 and the maximum value of the value averaged by eliminating the influence of the abnormal peak of a front step are held in a peak hold circuit 4. A control switch offset value V 2 in which a signal fluctuation part is considered for this value is added in an addition circuit 5 and this value is set as the control switch value of the optical amplifier. When a signal optical input value becomes lower than this value, this is detected by a comparator 9, a switch signal is added to a switch SW 11 and the gain of the optical amplifier is lowered by switching the control of an exciting light source drive circuit 8 from an output constant control circuit 12 to a low gain setting 10. As a result, an abnormal peak output is suppressed.

Shinji Sakano
Satoshi Aoki
Ichiro Yokota
Junya Kosaka
Yoshiaki Sato
Kazuo Aida

JP9867994A

February 18, 2002

May 12, 1994

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株式会社日立製作所
日本電信電話株式会社

H01S3/10; H01S3/13; H04B10/079; H04B10/29; H04B10/293; H04B10/294; H04B10/564; H04B10/572; H04L25/03; (IPC1-7): H04B10/04; H01S3/10; H04B10/06; H04B10/14; H04B10/16; H04B10/17

JP5199185A
JP7107034A
JP7240717A
JP4358443A

Kiyoshi Maruyama (7 outside)

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