Polarization-Related Statistics of Raman Crosstalk in Single-Mode Optical Fibers

Abstract

We present a novel comprehensive theory for the pump-to-probe interactions caused by the stimulated Raman scattering (SRS) in glass optical fibers. The developed theory applies to both the Raman gain with the un-depleted pump assumption and to the maximum loss induced by the Raman cross-talk (RXT loss). The latter is an effect that is the limiting propagation impairment in passive optical networks (PON). The main novelty of the paper is a rigorous mathematical analysis describing the interaction of SRS with the polarization evolution due to polarization mode dispersion (PMD). The Raman gain (or the RXT loss) is modeled as a random process for which a comprehensive theory is developed, giving for the first time to our best knowledge, an exact closed form expression for the mean and variance of the gain (or depletion) and a computationally efficient algorithm to numerically derive the gain probability density function. The developed theory is validated by the comparison with Monte Carlo analyses based on the wavelplate model for the optical fiber. The validation showed excellent agreement confirming the validity of the developed theory. As an example of application, we used our theoretical results to analyze next generation PON (NG-PON2) architectures, confirming that, in this scenario, RXT loss may be a limiting propagation effect.

Opportunities and Challenges of C+L Transmission Systems

“…Such scattering process is significant over spectral occupations of the order of few THz. Its first order effect on wavelength division multiplexed (WDM) optical signals is an energy transfer from higher frequency channels to lower frequency ones hence producing a tilt in the observed power spectrum of the WDM comb [27]. As SRS efficiency in silica core fiber is maximum for signals with a frequency separation of approximately 13 THz [26], it is relevant for multi-band systems, including C+L ones.…”