Patent ID: 7936999

Claim:
In a coherent optical receiver having a photodetector block for generating analog signals corresponding to each one of a pair of orthogonal polarizations of an optical signal received through an optical communications system, and a respective Analog-to-Digital (A/D) converter for generating a respective high-speed multi-bit digital sample stream corresponding to each analog signal, a method of at least partially compensating an effect of Polarization Dependent Loss (PDL) in the received optical signal, the method comprising steps of: tapping an output of each A/D converter to obtain a respective sample stream having a lower sample rate than the respective high speed multi-bit sample stream generated by the A/D converter; deriving, based on the tapped sample streams, a respective metric value indicative of a quality of each high speed multi-bit sample stream; and adjusting a power difference between the analog signals of each polarization, upstream of the respective A/D converter, based on the derived metric values.