In-service measurements of polarization-mode dispersion and correlation to bit-error 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 field-installed 43-Gb/s transmission system.