Optimal design of higher energy dissipative-soliton fiber lasers

We have numerically investigated dissipative soliton (DS) fiber lasers using the cubic complex Ginzburg-Landau equation (CGLE), and analyzed the effects of different parameters, including the cavity length (CL), the spectral filter bandwidth (SFBW), nonlinear phase shifts (ΦNL), and the initial fields. The results showed that for any initial input fields, once the stable output pulse was formed, the output pulse energy would increase with decreasing CL, or increasing ΦNL. When the pump power and CL parameters were fixed, there existed an optimal SFBW for which the highest output pulse energy could be obtained. In order to obtain higher pulse energy in a DS fiber laser, one can first fix the CL according to the required repetition frequency, then optimize the SFBW, and finally, increase the pump power, which corresponds to increasing the ΦNL. In simulations, using optimal parameters, a single pulse with energy of ~50 nJ, pulse duration of 10 ps, dechirped pulse duration of 37 fs, and pulse peak power of 1.4 MW was obtained.