Joint Optimization of 260km Unrepeatered Transmission System using Third Order DRA and ROPA

A joint optimization method is proposed for a 260 km unrepeatered transmission system using bidirectional third-order Raman amplifiers and remote optically pumped amplifiers. The simulation results show that the designed Raman amplifiers with the jointly optimized pump parameters obtain a loss budget of 54.98 dB and a gain flatness of 0.7398 dB. In the case of providing the same loss budget, the proposed joint optimization method improves the gain flatness by 0.634 dB. The proposed scheme provides a feasible alternative for the performance improvement of the future ultra-long unrepeatered transmission system.