| 摘要 |
An optical amplifier, for use with a data signal comprising a plurality of channels, controls output power by determining the number of channels in the data signal, choosing a target power in dependance upon the number of channels, and then controlling the gain of the amplifier such that an output power equals the target value. The number of channels in the data signal may be determined by a channel monitoring unit 200 which separates a monitor channel signal from the main data signal. Alternatively, the power of the data signal may be the measured to determine a change in the number of channels present. The gain of the amplifier may be controlled by controlling the input of a driving source, 233, 235. An output signal of the channel monitoring 200 unit may be converted into an optical signal and coupled to the output of the amplifier. The amplifier may comprise an erbium-doped optical fibre 233. The data signal may be a wavelength division multiplexed signal. |
