In-service measurements of polarization-mode dispersion and correlation to biterror rate

We introduce a nondisruptive in situ polarization-mode dispersion measurement technique using the sidebands of working channels and show that it compares favorably with the standard Mueller matrix method. Using this technique, we observed time correlations between the instantaneous differential group delay and bit-error rate on a 1000-km fieldinstalled 43-Gb/s transmission system.