Generation of dissipative solitons and self-similar pulses by a mode-locked fiber laser using a bandwidth tunable Mach-Zehnder interferometer filter

We suggest and demonstrate a scheme to generate dissipative solitons and self-similar pulses in a fiber laser mode-locked by nonlinear polarization rotation (NPR). The scheme is based on inserting a bandwidth tunable Mach-Zehnder interferometer (MZI) filter in the cavity. The MZI filter is fabricated by cascading two 3 dB optical couplers (OCs). The propagating light is split into two arms in the first OC and is combined again in the second OC. The free spectral range of the MZI, and the corresponding bandwidth of the MZI filter, depend on the optical path difference between these two arms. By applying stretching on one of the arms, both dissipative solitons and self-similar pulses have been obtained both numerically and experimentally. Furthermore, upon exploiting the dependence of the peak wavelength of the MZI filter on the amount of stretching, dissipative solitons with tunable wavelength have also been obtained.