An actively Q-switched all-fiber laser based on an acoustically modulated f
iber attenuator was implemented for producing 1550.5 nm pulses of 3 mu J in
pulse energy, 150 ns in pulse width, and 5 kHz in pulse repetition frequen
cy, The fiber attenuator was combined with a fiber Bragg grating, which was
used as the end mirror and the wavelength selector of the laser system, Th
e fiber attenuator was implemented with the excitation of transverse vibrat
ion by a modulated acoustic wave. The transverse vibration or micro bending
led to the coupling of the core mode and cladding modes. Through this mech
anism, the feedback level from the fiber grating or the Q factor of the las
er can be well controlled, The Q-switched fiber laser based on this scheme
can be quite simple.