Optimization of a dual pumped L-band erbium-doped fiber amplifier by genetic algorithm

A dual pumped L-band erbium-doped fiber amplifier (DPLB-EDFA) is investigated by solving the optical propagation equation that takes into account radial effects of the fiber and the rate equation in a steady-state two-level model with a weakly guided approximation. Applying an inversing method and a genetic algorithm, the DPLB-EDFA is optimized for dual pumped wavelengths and directions, fiber lengths, as well as radial distributions of the erbium concentration and core refractive index. There is evidence to show that the optimal pumping wavelengths of the DPLB-EDFA are different in two different pumping schemes. The optimized DPLB-EDFA is characterized by a gain peak wavelength of 1600 nm, a gain peak of ~34 dB, a bandwidth of 30-37 nm, and a noise figure of 3.5-3.7 dB. Such characteristics are superior as compared with those using conventional 1480-nm pumps with step indexes and radial-uniform erbium concentrations