Experimental Demonstration of Longitudinal Power Monitoring over a Mixed Fiber Link

This paper presents an experimental demonstration of the Linear-Least Squares Longitudinal Power Monitoring (LLS-LPM) technique over a mixed fiber link. The link is made by five spans, including four spans of G.652 Single-Mode Fiber (SMF) and one span of G.655 Non-Zero Dispersion-Shifted Fiber (NZDSF) with negative dispersion in the C-band. The study highlights the challenges posed by the negative dispersion of G.655 fiber and its impact on the convergence of the LLS-LPM algorithm. The experimental results demonstrate that the LLS- LPM algorithm can accurately estimate the power profile, only in the link portion where there is a one-to-one relation between the cumulated chromatic dispersion and the distance. This work provides valuable insights into the application of LLS-LPM in real-world fiber networks with mixed fiber types.