Polarimetric Characterization of RF Spectra at the Output of Linear Optical Systems

The polarization properties of the optical RF spectrum at the output of linear systems are studied both theoretically and experimentally. An analytical expression for the RF spectra of the Stokes parameters for sources of general statistics is derived. Specific formulas are calculated for broadband sources of Gaussian statistics and laser sources with predominant phase noise. In addition, a novel technique for characterizing the polarimetric dependence of the RF spectra is introduced. The technique is especially suitable for use in deployed links since it can use the communication signal, no prior knowledge of the signal statistics is necessary, and no access to the transmitting end is required. Using the formalism, estimation of the output principal states of polarization from RF measurements is demonstrated