Patent ID: 8422882

Claim:
A method for monitoring a polarization mode dispersion (PMD) effect in an optical signal, comprising: splitting an input optical signal with an input optical signal bandwidth into a first optical signal with a first optical signal bandwidth less than the input optical signal bandwidth and a second optical signal with a second optical signal bandwidth different from the first optical signal bandwidth, wherein the first optical signal and the second optical signal are centered at a common optical wavelength which is at a center of signal spectral bands of the first optical signal with the first optical signal bandwidth and the second optical signal with the second optical signal bandwidth; measuring a degree of polarization of the first optical signal and a degree of polarization of the second optical signal, respectively; and processing the measured degree of polarization of the first optical signal and the measured degree of polarization of the second optical signal to determine a depolarization factor of the input optical signal to reflect the PMD effect in the input optical signal and to determine an optical to signal noise ratio of the input optical signal.