Patent ID: 8406637

Claim:
An optical system comprising: a wavelength division multiplexed (WDM) transmitter comprising a plurality of transmitters for transmitting a plurality of optical signals; and a control processor for calculating a desired value of a quality metric for each optical signal of the plurality of optical signals, and for transmitting the desired value to each transmitter; wherein each transmitter comprises: an optical source for transmitting a corresponding optical signal of the plurality of optical signals; an interface for receiving a measured value of a quality metric of the corresponding optical signal and for receiving the calculated desired value of the quality metric from the control processor so that a drive power of the optical source is adjusted within a region of linear operation such that the measured value equals the desired value, wherein the transmitters are arranged into one or more bands, each band comprising one or more transmitters and comprising a band gain amplifier, and wherein the control processor is adapted to apply a centralization signal to the one or more transmitters in a given band in order to maintain an average drive power for that band, and the band gain amplifiers are configured to compensate for the effect of the centralization signal.