Numerical modeling of three-level system in ytterbium-doped photonic crystal fiber laser

Abstract

In order to investigate the power characteristics of the Yb-doped photonic crystal fiber(PCF) laser, we have represented a simple three-level system modeling based on a rate equation model. According to our theoretical modeling, the variation of the output power Pout via the pump power Pp is theoretically studied, which agrees well with experimental data. Then, we have investigated the effects of the doped concentration of Yb ions, the length and the effective mode field area of the PCF on the output power Pout of the Yb-doped PCF laser, respectively. The results show that the output power Pout first increases and then decreases when the doped concentration of Yb ions N0 increases and when the pump power Pp and the length of the PCF L are constant. And the optimal doped concentration Nm exponentially decreases when the length L of the PCF increases and the slope of the optimal doped concentration Nm also decreases when the length L of the PCF increases. The output power Pout first increases and then decreases when the length of the PCF L increases and when the pump power Pp and the doped concentration N0 are constant. And the optimal length Lm of the PCF exponentially decreases when the doped concentration N0 increases and the slope of the length of the PCF also decreases when the doped concentration N0 increases. The output power Pout linearly decreases when the effective mode field area A increases.