为探索锗激光器的性能优化方案，建立了基于双轴张应变的双异质结法布里 －珀罗电激励式边缘发射锗激光器模型． 通过该模型讨论了双轴张应变与最优掺杂密度的
关系，分析了不同双轴张应变和掺杂条件下阈值电流密度、电光转换效率等激光器参数的变化． 结果表明: 最优掺杂密度随着双轴张应变的增大而减小，过高的掺杂则导致激光器工作性能的下降; 在同等掺杂条件下，光增益以及增益的峰值波长会随着双轴张应变的增大而增大; 与文献数据相比，在 0． 8% 双轴张应变和对应的最优掺杂密度( 8 × 10¹⁹cm^-3 )下，锗激光器的阈值电流密度降低至文献数据的 1/10，电光转换效率提升了约 10 倍．

In order to explore a performance optimization scheme for germanium laser,firstly,a model of double- heterojunction Fabry-Perot electrically-pumped edge emitting germanium laser is established on the basis of biaxial- ly-tensile strain.Then,the relationship between the biaxially tensile strain and the optimal doping density is dis- cussed with the help of the proposed model.Finally,the variations of such laser parameters as threshold current density and electro-optical conversion efficiency with both biaxially-tensile strain and doping density are analyzed.The results show that ( 1) the optimal doping density decreases as biaxially-tensile strain increases,and,excessive doping may lead to laser performance degradation; ( 2) at the same doping density,both optical gain and peak gain wavelength increase as biaxially-tensile strain increases; and ( 3) in comparison with the literature data,germanium laser with 0. 8% biaxially-tensile strain and with the corresponding optimal doping density ( 8 ×10¹⁹cm^-3 ) posses- ses a threshold current density as low as 1/10 of that of the literature value,while the electro－optical conversion efficiency nearly increases by 10 folds.