An ytterbium-doped fiber laser at 1.1 um

A pulsed ytterbium-doped fiber laser is proposed and developed. A length of samarium-doped fiber was inserted into the laser cavity to induce passive Q-switching. The laser oscillated in the continuous wave, Q-switched mode-locked or Q-switched regime depending on adjustment of the intracavity polarization controller and the pump power. Q-switched pulses with a pulse energy of ~7.5 nJ and duration of ~70 ns were obtained at a pump power of ~1500 mW, corresponding to a peak output power of ~106 mW at an average power of 2 mW. The low output power was attributed to the low coupling efficiency of pump radiation into the cavity and the high cavity losses. All results were obtained at room temperature