Generation of a feedback signal for a polarization mode dispersion compensator in a communication system using alternate-polarization

摘要

The invention relates to a method of generating a feedback signal for adjusting a polarization mode dispersion compensator (PMDC, 21) in a transmission system with alternate-polarization. A first signal (37) is determined by measuring a spectral component of the radio frequency modulation of an optical signal (33) at a particular radio frequency. Preferably, the radio frequency essentially corresponds to half the symbol rate of the optical signal (33). Also a second signal (35) is determined by coupling the optical signal (33) into a delay line interferometer (DLI, 50) having a delay essentially corresponding to the symbol period or an odd multiple of the symbol period between its arms (51, 54). Downstream of the DLI (50), the signal is optical-to-electrically converted. Downstream of the optical-to-electrical conversion, an intensity measurement is performed. The first (37) and second (35) signals are then combined to generate the feedback signal (28).

主权项

1. A method of generating a feedback signal, the feedback signal for adjusting a polarization mode dispersion compensator and the feedback signal based on an alternate-polarization optical signal, the optical signal being downstream of the compensator, the method comprising the steps of:
determining a first signal
by measuring a spectral component of modulation of the optical signal or of a signal based thereon, wherein the modulation is at a radio frequency; determining a second signal
by coupling the optical signal into a delay line interferometer providing between its arms a delay corresponding to a symbol period or an odd multiple of the symbol period,by optical-to-electrical converting downstream of the delay line interferometer, andby intensity measuring downstream of the optical-to-electrical conversion; and combining the first signal and the second signal, thereby generating the feedback signal.