Q-switching of Yb3+-doped fiber laser using a novel micro-optical waveguide on micro-actuating platform light modulator

We report a novel micro-optical waveguide ( MOW) on micro-actuating platform ( MAP) light modulator for Q-switched all-fiber laser applications. The light modulator employs a fused biconical taper (FBT) coupler, which acts as MOW, mounted on an electromechanical system, MAP, where an axial stress over the waist of FBT coupler is precisely controlled to result in modulation of output power. The modulator was implemented in a clad pumped Yb3+-doped fiber laser cavity as a Q-switching element. Q-switching was successfully achieved at the repetition rate of 18.6kHz and average pulse energy of 1.4 mu J. The proposed structure can be readily applied in power scaling up of all-fiber Q-switching laser systems. (c) 2005 Optical Society of America.