100-Tb/s-Class C+L+U-Band NZ-DSF Transmission With Closed-Form- GN-Model-Based Launch Power Optimization

We investigate 100-Tb/s-class C+L+U-band 14.85-THz bandwidth inline-amplified transmission over non-zero-dispersion-shifted fiber (NZ-DSF). The WDM signal bandwidth is extended to the U-band away from the zero-dispersion wavelength to boost the total throughput. The bandwidth extension to the U-band is enabled by a U-band repeater composing periodically poled lithium-niobate-based optical parametric amplifiers (PPLN-OPAs) and erbium-doped fiber amplifiers (EDFAs). The launch power of the C+L+U-band WDM signal is optimized by calculation accounting for stimulated Raman scattering and the wavelength-dependent accumulation of amplified spontaneous emission noise from PPLN-OPAs and EDFAs and nonlinear interference from NZ-DSF transmission to maximize the total throughput. To select an appropriate calculation method for launch power optimization, we analyze the impact of multi-channel interference, which is ignored in most closed-form expressions of the Gaussian noise (GN) model. We experimentally demonstrate net bitrates of 115.6 and 101.4 Tb/s after 240- and 400-km NZ-DSF transmission with bandwidth extension to the U-band and launch power optimization using a closed-form GN model.