05117196 is referenced by 40 patents and cites 9 patents.

The gain of an optical amplifier is maintained constant by employing a portion of the amplified optical signal in a feedback loop. In one arrangement this is used to control the output of a pump signal source accordingly. The portion of the said signal corresponds to spontaneous emission (ASE) at a control wavelength or band of wavelengths different to the wavelength of the optical signal output. In the case of an erbium, for example, optical fibre amplifier the portion is preferably ASE at 980 nm, the amplified signal being at 1.535 .mu.m, i.e. completely different transitions in the amplifying medium are used for gain and ASE feedback in order to lessen requirements on the filter used to extract the portion for the feedback loop.

Title
Optical amplifier gain control
Application Number
7/512960
Publication Number
5117196
Application Date
April 23, 1990
Publication Date
May 26, 1992
Inventor
Nigel Taylor
London
GB
Robert A Baker
London
GB
Kevin C Byron
Stortford
GB
Richard E Epworth
Stortford
GB
Agent
Lee Mann Smith McWilliams & Sweeney
Assignee
STC
GB
IPC
H01S 3/13
H01S 2/20
H01L 15/00
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