Stabilization of a multi-channel optical signal transmitter through correlation feedback

摘要

Methods and apparatus for stabilizing or otherwise controlling optical signal power levels in a multi-channel optical communication system. A multi-channel optical signal is detected in a single receiver, and the resulting detected signal is supplied to a correlator. The correlator correlates the detected multi-channel signal with a data signal associated with a particular channel to be controlled in order to generate a measure of the optical signal power of the particular channel. The measure is utilized in a feedback control loop to control an optical signal power level of the particular channel. The correlator may generate the measure of optical signal power by mixing the detected signal and the data signal in an RF mixer, by multiplying the detected signal and a data signal in the form of a unique identifier associated with the particular channel, or by using other suitable correlation techniques. A feedback control processor may be used to process the measure to generate a control signal which is applied to a current source generating current for the particular channel in a multi-frequency laser or other multi-channel optical source. The processor may sequentially monitor and control each of the multiple channels of the multi-channel optical signal using the same receiver and correlator.