Numerical analysis and characterization of fiber Bragg grating-based Q-switched ytterbium-doped double-clad fiber lasers

A numerical model of the fiber Bragg grating (FBG)-based actively Q-switched double-clad fiber laser is presented in this paper. Based on numerical simulations, the influence of FBG on Q-switched pulse performance of Yb3+-doped double-clad fiber laser is studied, the pulse characteristics are discussed and analyzed using different FBG profiles, and further investigation is conducted to study the pulse characteristics of the fiber lasers under varying Q-switching conditions, including repetition rates, apodization profiles of FBG, peak reflectivity of the tunable FBG, cavity length and pump power.