Investigation on different type of pulses due to strong third order dispersion effect in mode-locked fiber lasers

Here we have numerically investigated the pulse property in a wavelength switchable mode-locked fiber laser which is achieved with a tunable filter. Owing to the strong third-order dispersion (TOD) of dispersion-compensating fiber, the net cavity group velocity dispersion of the proposed fiber laser can be manipulated and exhibits wavelength-dependent feature. Our findings indicate that different types of pulses, including conventional solitons, dispersion-managed solitons, and dissipative solitons, can be achieved, and switched in various wavelengths. The pulse characteristics including pulse width and spectrum bandwidth have been investigated, in addition to with the intracavity dynamics. The influence of the length of dispersion-compensating fiber is also investigated. These results provide an excellent foundation for understanding the formation dynamics of various pulse waveforms in the laser cavity and help the development of a multi-wavelength fiber laser with a strong TOD cavity.