Numerical demonstration of generation of bound solitons in figure of eight microstructured fiber laser in normal dispersion regime

We have numerically studied passive mode locking in figure of eight laser containing microstructured optical fiber. We demonstrate for the first time to the best of our knowledge the generation of bound states in such configuration in the normal dispersion regime. The numerical simulations are based on extended nonlinear Schrödinger equation using the symmetrized split-step Fourier method. The numerical results show that single pulse or bound solitons can be obtained when the parameters of the cavity are suitably chosen. We identify the small signal gain and the microstructured optical fiber's nonlinear coefficient as key parameters for the generation of bound solitons in figure of eight fiber laser.