16-μm-wavelength dissipative solitons mode-locked fiber laser based on the optimization of passive fibers distribution

We present the results of numerical simulation of a dissipative solitons mode-locked fiber laser working over 1.6 μm. First, systematic and computationally intensive analysis of high-energy-pulse nonlinear phase shift of a fiber laser was conducted, and we numerically simulated dissipative solitons pulse evolution. In addition, we employed a method named A/B ratio to decrease B-integral by changing the distribution of passive fiber in the ring cavity. This method inhibited the accumulation of nonlinear phase shift and effectively enlarged the pulse energy from 0.8 nJ to 3.6 nJ. Finally, we optimized linear chirp of the pulse by using a designed larger-mode-area fiber, and ultimately a 2.82-kW, 650-fs pulse was obtained.