Multichannel stabilization of an integrated WDM laser transmitter through correlation feedback

The output optical signal power in each channel of an integrated multifrequency laser can be estimated by correlating the total laser output signal with channel data using an optical receiver and an RF mixer. This correlation signal was used in a feedback loop to equalize and stabilize an eight-channel 50-Mb/s 1550-nm wavelength-division multiplexed (WDM) multifrequency laser. The method also works with broadcast data by introducing relative time delays between the channels to decorrelate their data.