440 fs, 92 GHz regeneratively mode-locked erbium fiber laser with a combination of higher-order solitons and a SESAM saturable absorber

We report a regeneratively FM mode-locked erbium fiber laser operating at 9.2 GHz, in which a SESAM saturable absorber and a higher-order soliton effect are combined to generate a 440 fs pulse train. Higher-order solitons have a narrow center peak while accompanied by pedestals on the wing, but such components can be well suppressed by the saturable absorber, which enables very efficient pulse narrowing. As a result, 440 and 480 fs transform-limited sech pulses were successfully obtained at output powers of 15 and 45 mW, respectively.