Information spectral efficiency and launch power density limits due to fiber nonlinearity for coherent optical OFDM systems

Abstract

We derive closed-form expressions for nonlinear transmission performance of dual-polarization closely spaced coherent optical orthogonal frequency-division multiplexing (CO-OFDM) systems. We find that the fiber nonlinear noise exhibits a signature of the flicker noise or 1/f noise beyond the corner frequency that is inversely proportional to the total participating bandwidth. We derive a noise enhancement factor that captures the interference effect of nonlinear noises among different spans. For a 10 × 100-km standard single-mode-fiber (SSMF) link with no dispersion compensation at an optimal launch power density of - 15.9 dBm/GHz, the spectral efficiency of 9.90 b/s/Hz can be achieved for d..