To substantially reduce gain difference due to pump optical wavelength.
A transfer system comprises a transmitter and a receiver connected with an optical fiber. A plurality of optical amplifiers are arrayed along the optical fiber between the transmitter and the receiver for amplifying signal channel. Each amplifier comprises a pump light source, and its wavelength is such that a gain difference due to pump optical wavelength related to effect is substantially reduced. A WDM transmission system comprising a transmission channel containing longitudinal succession of the optical amplifier is also stated. Relating to a gain spectrum of the amplifier, at least a part of it is controlled by a feedback loop 25 which controls temperature of a laser diode pump 21. The feedback loop 25 derives a control signal based on measurement of for example, a drive current applied to the pump, emission wavelength of the pump, or none-equilibration between the output power from amplifier in one of multiplex signal channels and that from at least one of other channels, etc.
DAVIS FIONA
HABEL RICHARD A
JAKOBSON PAUL A
JOLLEY NIGEL E
KEYS ROBERT W
ROBERTS KIM BYRON
NEWHOUSE MARK A
YADLOWSKY MICHAEL J
NORTHERN TELECOM LTD
| JPS6169960U | ||||
| JPS3531041Y1 | ||||
| JPS4420921Y1 | ||||
| JPS5110143U | ||||
| JPS62252702A |
| EP0125471A2 |
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