Mode-locked ytterbium-doped linear-cavity fiber laser operated at low repetition rate

This paper reports an ytterbium-doped linear-cavity fiber laser with the optical length of 1.6 km passively mode-locked by a high modulation depth semiconductor saturable absorber mirror (SESAM). An ultra-low repetition rate of 191 kHz was achieved. The laser delivered the highly-chirped output pulses with the energy up to 75.2 nJ.