Theoretical and experimental comparison of different configurations of tapered fiber lasers

Recently, we have proposed an active tapered fiber as a medium for light generation and amplification. Using the active tapered double clad fiber (T-DCF) we have demonstrated a high-power CW fiber laser, amplifier and actively Q-switched high-energy fiber laser [1–3]. The model of light generation (amplification) and pump absorption in T-DCF has been developed earlier by exploiting the ray optics approach [1,3]. The ray optics model of a fiber laser with T-DCF has certain limitations. In presented work, we discuss a model of the T-DCF fiber laser based on rate equations, and a previously developed mode-based model of light propagation in a tapered fiber [4].