Peak Power and Pulse Shape of an Active Q-Switched Fiber Laser Based on Overlap of Narrow Filters

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
³⁺
)-doped fiber laser configuration. We use a traveling-wave numerical model to study the peak power, the time duration and the pulse shape of the output pulses with respect to the cavity parameters, such as the Er
³⁺
-doped fiber length, the pumping power, and the scanning frequency of the fiber F–P tunable filter. The peak power values of 1.8 W, 5.4 W and 5.9 W were obtained for pump powers of 40 mW, 60 mW and 100 mW respectively.