WDM monitoring technique using adaptive blind signal separation

We present a cost-effective method to monitor the performance of wavelength-division-multiplexed (WDM) channels. The method is based on simple optical signal processing in a combination with electronic signal processing. The photocurrent of a detected (multichannel) optical signal is analyzed using an adaptive blind signal separation method. A maximum data decorrelation criterion is used to separate the WDM channels. We show experimentally that four WDM channels can be reconstructed accurately by this numerical method.