CdSe/ZnS量子点非饱和单模光纤激光器的数值建模

Numerical Modeling of an Unsaturated Single-Mode Fiber Laser Doped with CdSe/ZnS Quantum Dots

提出了一种新型的光纤激光器———量子点光纤激光器(QDFL)。以CdSe/ZnS量子点作为激活增益介质,基于实验观测到的量子点的吸收和发射谱,建立了二能级系统的粒子数速率方程和光功率传播方程,并进行数值求解。应用遗传算法,以激光输出功率为目标函数,优化得到了QDFL的最佳掺杂浓度、光纤长度、出射镜反射率和抽运光波长。与传统的掺钕光纤激光器相比,QDFL掺杂的饱和浓度较低、光纤的饱和长度较短、抽运效率更高。当抽运功率为2W时,模拟计算得到的激光输出功率可达1.5W。通过多粒度掺杂,单波长的QDFL可发展为一种新型的多波长激光器。

A novel fiber laser——quantum-dot-doped fiber laser（QDFL） is presented.A two-lever system is established based on the observed single-peak photoluminescence of the CdSe/ZnS quantum dot（QD） that is used as the active medium.The optimal parameters（doping concentration,fiber length,reflectivity of output mirror,pump wavelength） of QDFL are determined by solving the rate equations and the power propagation equations in the two-level system,using a genetic algorithm and taking the laser output power as an objective function.Compared with the conventional Nd3＋-doped fiber laser,QDFL shows a lower saturated doping concentration,a shorter saturated fiber length and a higher pump efficiency.Upon a pump power of 2 W,the simulated laser power of QDFL can reach 1.5 W.Further,such a single-wavelength QDFL can be developed into a novel multi-wavelength laser in multiple sized doped cases.