Dissipative soliton resonance in a figure-eight multimode fiber laser.

We report, for the first time to the best of our knowledge, a spatiotemporal mode-locked (STML) multimode fiber laser based on nonlinear amplifying loop mirror (NALM), generating dissipative soliton resonance (DSR) pulses. Due to the complex filtering characteristics caused by the inherent multimode interference filtering structure and NALM in the cavity, the STML DSR pulse has wavelength tunable function. What's more, kinds of DSR pulses are also achieved, including multiple DSR pulses, and the period doubling bifurcations of single DSR pulse and multiple DSR pulses. These results contribute to further understand the nonlinear properties of STML lasers and may shed some light on improving the performance of the multimode fiber lasers.