Analysis of capacity upgrading in L-band using power control strategy

To further increase the capacity of optical communication systems and networks with currently installed fibers, the L-band transmission needs to be exploited because the C-band spectral resource is going to be exhausted. From the perspective of network planning by operators, efficient estimation of increased capacity brought by added L-band channels is indispensable to evaluate the overall performance and cost. However, stimulated Raman scattering (SRS) arises for ultra-wideband transmission, which induces power transfer between low- and high-frequency channels. Moreover, the number of added L-band channels has an influence on the overall system performance through fiber nonlinearity. Above factors render the analysis of capacity upgrading beyond the mature C-band-only transmission a nontrivial task. In this letter, an analysis of capacity upgrading in L-band is provided using power control strategies including the local optimization global optimization (LOGO) algorithm and power offset and tilt control by OAs. It is found that with power control based on the LOGO results, not only quasi-linear capacity increase with the L-band channel number is provided, but higher overall capacity can be achieved compared with that with LOGO-only scheme.