Multiple-soliton dynamic patterns have been observed experimentally in an erbium-doped fiber ring laser with graphene as a saturable absorber. Under relatively low pumping power we have obtained disordered multiple-solitons, bunched solitons and high order harmonic mode locking by adjusting the orientation of the polarization controllers. With increased pumping power, we have also observed flow of solitons. We have experimentally investigated in detail the conditions under which these patterns form.

We have investigated experimentally different operational states of an all-normal-dispersion ytterbium-doped fiber (YDF) ring laser with a long cavity. Various operational states were obtained by adjusting a polarization controller (PC) and the pump power. Self-pulsing, bright pulses, dark-bright pulse pairs and their harmonic mode locking (HML) counterparts, as well as dark pulses and their HML counterparts have all been obtained. Numerical simulations reproduce well the formation processes of dark pulses and dark-bright pulse pairs.

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We have proposed and demonstrated an L-band passively harmonic mode-locked fiber laser based on a graphene saturable absorber (SA). By adjusting the pump power and the polarization controller, we have experimentally observed Lband fundamental and harmonic mode-locked optical pulses. The fundamental optical pulse has the duration of 1.3 ps, and the maximum average output power of 13.16 mW at the incident pump power of 98.8 mW. The order of the harmonic mode-locked optical pulses can be changed over the range from the second to the fourth. From the experimental results, we deduced that the likely origin of the harmonic mode-locked selfstabilization was the result of global and local soliton interactions induced by the unstability continuous wave (CW) components. c

We report on the experimental observation of bound states of solitons in a graphene mode locked erbium doped fiber laser. By using graphene as a saturable absorber, we have obtained stable, single and bound soliton pulses, the latter with a full width at half maximum (FWHM) of 1.49 ps and a fixed pulse sep aration of 2.46 ps. Our results once again show that bound soliton pulses is an intrinsic feature of fiber lasers independent of the exact mode locking mechanism.