High wavelength-resolved state of polarization monitoring method based on stimulated Brillouin scattering effect

A state of polarization (SOP) monitoring method with high wavelength resolution, based on the stimulated Brillouin scattering (SBS) in optical fiber is presented. By scanning the wavelength of pump which stimulates SBS effect, the signal spectrum with high resolution of ~ 0.1 pm can be obtained. Then, through measuring the signal spectra under six specific polarization states of pump, the Stokes vectors of each wavelength component of signal are retrieved. The results show that a mean error which is 0.018 is achieved for the wavelength-resolved SOP monitoring of a 40-Gb/s nonreturn-to-zero differential quadrature phase-shift keying (NRZ-DQPSK) signal. This monitoring method provides effective capability for estimation of polarization mode dispersion (PMD).