Dynamic behavior of a short cavity single-mode erbium-doped fiber laser

Erbium-doped fiber laser as a novel light source and optical amplifier has been widely used in optical fiber communications and optical fiber sensors. Erbium-doped fiber lasers have attracted much attentions for their unique dynamic behaviors and applications. The nonlinear dynamic behavior of a short cavity erbium-doped fiber laser is studied in this paper. The idea of additional degrees of freedom is used to simplify the laser mode to study the dynamics of erbium-doped fiber laser. The three-level mode of the laser is simplified to a two-level mode, and a dynamic physical model of erbium-doped fiber laser is established by using pump periodic excitation. The laser can generate periodic pulses and chaotic pulses when a periodic signal of square wave as a periodic pulse is exciting the pump. The periodic pulsation, quasi-periodic behavior and chaotic behavior of laser under the various conditions are analyzed. It is found that the pump excitation level and its frequency are the main factors that determines the nonlinear dynamics of the laser, and the changes of pump excitation level and frequency will change the dynamic behavior of the laser. The effects of pump intensity, erbium doping concentration and photon lifetime on the dynamics behavior of laser are also discussed. When a large number of numerical calculations and simulations are operated, it is found that the quasi-periodic region and chaotic region are determined by the pump excitation level and frequency. The results have important reference value for erbium-doped fiber laser and laser technology and laser chaos application.