Abstract: Fibered Q-switches are critical components of Q-switched all-fiber lasers.Presently,the useful fibered Q-switches mainly include passive Q-switches based on stimulated Brillouin scattering (SBS) effect,active Q-switches based on two-beam interference principle and some active Q-switches in special design.The repetition rates of the Q-switches based on SBS effect are not stable and adjustable.The Q-switches based on two-beam interference principle belong to slow Q-switches.Because the technologies of other active Q-switches are not yet mature,it is inevitable to develop active fibered Q-switches with high efficiency.