DETERMINING IN-BAND OPTICAL SIGNAL-TO-NOISE RATIOS IN OPTICAL SIGNALS WITH TIME-VARYING POLARIZATION STATES USING POLARIZATION EXTINCTION

摘要

A method and apparatus for improving the accuracy of in-band OSNR measurementsusing aconventional polarization extinction or polarization-nulling method. Inparticular, the severedegradations of the polarization extinction that result from slow and fastpolarization fluctuationsin the optical signal components during the in-band OSNR measurement aresubstantiallymitigated by rapidly and/or randomly changing the state of polarization priorto conventionalpolarization control and filtering.