Fiber effective core area impact on reducing nonlinear distortion and Raman noise of 42.7 Gb/s RZ-DPSK over 360 km bidirectional Raman span

Abstract

The propagation model of repeaterless ultra-long span transmission system using bidirectional Raman amplifier is presented. General formulation of Raman gain, optical signal power, nonlinear phase shift, and optical signal to noise ratio as a function of fiber effective core area are analytically investigated. Numerical analysis results demonstrate the advantage of large effective core area on reducing nonlinear phase shift and Raman noise that lead to the enhancement of transmission performance. An application model based on computer simulation on repeaterless single transmission span over 360 Km propagation distance of 42.7 Gb/s RZ-DPSK modulated signal is examined. Computer simulation result demonstrates transmission performance of large effective core area fiber is better than small effective core area fiber that exactly matches to numerical analysis prediction.