考虑增益饱和及载流子复合效应优化设计多量子阱激光器

Analysis on effects of gain saturation and carrier recombination optimum design for multi quantum well lasers

采用光增益与载流子浓度的对数关系，在受激发射速率中分别引入了增益饱和项和载流子的复合项，通过适应于多量子阱激光器的速率方程，从理论上证明了对于短腔结构的激光器，阈值电流存在最小值。文中三种表述与阈值电流最小值对应的最佳阱数具有相同的表达式。讨论了阈值电流密度、最佳阱数等与器件参数（阱数、腔长和反射率等）之间的依赖关系。结果表明减少激光器的腔长，提高反射率有利于降低阈值电流。这将对量子阱激光器的研究和优化器件结构有所裨益。

Based on changing the logarithmic relation of gain on carrier density, the stimulated emission rate includes a gain saturation term as well as the carrier recombination term. It has been proved that there exists the minimum threshold current for short lasing cavity. In above three equations, an optimal well number for the minimum threshold current are the same. The relation of device parameter on threshold current and optimal well numbers have been discussed. It has been found that decreasing the cavity length and increasing the reflectivity can reduce threshold current. The result is benefit for lasers both in theoretical analysis and the device structures.