Numerical study of an actively harmonic mode-locked fiber ring laser with SOAs

An actively harmonic mode-locked fiber ring laser is presented in this paper, It consists two semiconductor optical amplifiers (SOAs), one is named modulation SOA, the other is named gain SOA. The material gain profile, spatial distribution of carriers and the broad-band spontaneous noise emission are considered in the model. The results of theoretical study and numerical simulations reveal that 7.5ps stable mode-locked pulse trains with repetition rate of 20GHz can be obtained, and the wavelength of pulse trains are over 40nm tuning range.