Experimental study of injection seeded single-longitudinal-mode Q-switched fiber laser

-The role of injection seeding power on the operation and output characteristics of a single-longitudinal-mode (SLM) injection seeded Q-switched fiber laser is investigated. The mode coupling between seeding laser and the potential longitudinal-modes of the oscillator changes as the injection seeding power increase. So the Qswitched laser may operate at different regimes which can be distinguished by the pulse features. Only with a proper range of injection seeding power that is not too larger or too small, the operation of injection seeded Qswitched fiber laser with narrow-linewidth, high peak power and narrow pulsewidth laser pulses is possible. The Q-switched fiber laser linewidth is narrowed through inserting a dual-OCs oscillator into the laser cavity. 200-ns, 1-W peak power SLM Q-switched laser pulse with nearly transform-limited linewidth is obtained when the pump power is 300 mW.