Versatile long cavity widely tunable pulsed Yb-doped fiber laser with up to 27655th harmonic mode locking order.

We report flexible dissipative soliton generation from an all-fiberized all-normal-dispersion (ANDi) long cavity actively mode locked ytterbium doped fiber laser based on improved harmonic mode locking technique. The laser is featured with unusually wide and fine tunabilities in repetition rate and operating wavelength, meanwhile superior stability is maintained. The repetition rate of the laser can be flexibly controlled from 226 kHz to 6.25 GHz (corresponding to the highest 27655th order harmonic mode locking) in the interval of 226 kHz, while supermode suppression is confined above 50 dB and the pulse duration is retained in the range of 38 ps~80 ps. As high as 4.3 nJ pulse energy can be achieved with a low pump power of 160 mW when operating at the fundamental mode locking regime. The operating wavelength of the laser can be tuned in the wide range of 1005 nm~1100 nm. As far as we know, it is the first demonstration of up to ten thousands order stable harmonic mode locking in ANDi fiber laser, which manifests the capability of generating both high energy pulse and ultra-high repetition rate pulse in a single ANDi cavity. The destabilization of dissipative soliton under strong pump is also demonstrated.