This work presents theoretical and experimental studies on Q-switched and mode-locked pulse generation in fiber cavity with saturable absorber (SA). The fundamental principles of fiber laser systems are outlined, which include fiber modes, losses in fiber, and fiber dispersion and nonlinearity. The various nonlinear refractive index effects in addition to the other two important nonlinear scattering effects; stimulated Raman scattering and stimulated Brillouin scattering are discussed. Moreover, the characteristics of the laser gain medium and the basis of SA are outlined. The basics of laser...