The investigated Q-switching technique is based on the spectral overlap between a Fabry–Perot (F–P) filter and a fiber Bragg grating. This Q-switching concept is implemented in a ring erbium (Er)-doped fiber laser configuration. We use a traveling-wave analytical model to study the peak power and the time duration of the output pulses with respect to the cavity parameters, such as the Er-doped fiber length, the pumping power, and the scanning frequency of the fiber F–P tunable filter. Experimental results are used to validate the proposed Q-switched fiber laser model.