Patent ID: 7206517

Claim:
A method of polarization-scrambling an incoming optical signal, comprising the steps of: causing a variation of the state of polarization (SOP) as a function of time for an incoming optical signal that has an unknown SOP to produce a polarization-scrambled optical signal; periodically changing said SOP of said polarization-scrambled optical signal with time, such that said periodically changing polarization-scrambled optical signal covers approximately an entire Poincaré sphere surface during each time period of said periodic changing, over a plurality of periods; propagating said periodically changing polarization-scrambled optical signal through a fiber-optic transmission link that contains polarization dependent loss (PDL); producing a periodic variation as a function of time of the optical signal power of said polarization-scrambled optical signal propagating through said fiber-optic transmission link; and measuring said optical signal power variation in real time.