Active Q-switching of an all-fiber ring laser utilizing a novel in-fiber acousto-optic tunable bandpass filter (AOTBF) is reported. The transmission characteristics of the AOTBF are controlled by amplitude modulation of the acoustic wave; the device exhibits a 3-dB power insertion loss, 0.91-nm optical bandwidth, and 28-dB nonresonant light suppression. Cavity loss modulation is achieved by full acousto-optic mode re-coupling cycle induced by traveling flexural acoustic waves. When the acoustical signal is switched on, cavity losses are reduced, and then, laser emission is generated. In addition, by varying the acoustic wave frequency, a wide wavelength tuning range of 30.7 nm is achieved from 1542 to 1572.7 nm. The best Q-switched pulses were obtained at 1.1-kHz repetition rate, with a pump power of 242 mW, at the optical wavelength of 1569.4 nm. A maximum pulse energy of 8.3 μJ at an average output power of 9.3 mW was achieved, corresponding to optical pulses of 7.8-W peak power and 1-μs temporal width