GaAs/AlGaAs环形激光器的量子阱结构优化

为了研究量子阱结构对半导体环形激光器阈值电流的影响,从F-P腔激光器的振荡条件出发,分析了半导体环形激光器的阈值电流密度与量子阱结构参量的函数关系,并推导出最佳量子阱数的表达式。利用器件仿真软件ATLAS建立环形激光器的等效模型,仿真、分析了不同工作温度下,量子阱数、阱厚及势垒厚度对阈值电流的影响。结果表明,阈值电流随量子阱数和阱厚的增加先减小后增大,存在一组最佳值;在确定合适的量子阱数和阱厚后,相对较窄的势垒厚度有助于进一步降低阈值电流;采用GaAs/AlGaAs材料体系和器件结构,其最佳量子阱结构参量为M=3,dw=20nm及db=10nm。

Optimization of quantum well structure for GaAs/AlGaAs ring lasers

In order to study effect of multiple quantum well (MQW) on threshold current of a semiconductor ring laser (SRL), the function relationship between threshold current of SRL and MQW structural parameters was analyzed based on the oscillation condition of a conventional Fabry-Perot laser. An optimal expression of quantum well number was derived. Equivalent model of SRL was founded by utilizing device simulation software ATLAS. The effect of quantum well number, well width and barrier thickness on threshold current density of SRL were simulated and analyzed at various operating temperatures. The simulation results show that threshold current decreases firstly and then increases with increasing of well number and well width. A set of optimal values existed. After determining the appropriate well number and well width, the barrier with relatively narrower thickness can further reduce the threshold current. For GaAs/AlGaAs material system and device structure, the optimal parameters are M=3, dw=20nm, and db=10nm respectively.