中文摘要：

Optical gain characteristics of Ge1xSnμx are simulated systematically.With an injection carrier concentration of 5×1018/cm3 at room temperature,the maximal optical gain of Ge0.922Sn0.078 alloy(with n-type doping concentration being 5×1018/cm3) reaches 500 cm-1.Moreover,considering the free-carrier absorption effect,we find that there is an optimal injection carrier density to achieve a maximal net optical gain.A double heterostructure Ge0.554Si0.289Sn0.157/Ge0.922Sn0.078/Ge0.554Si0.289Sn0.157 short-wave infrared laser diode is designed to achieve a high injection efficiency and low threshold current density.The simulation values of the device threshold current density Jthare 6.47 kA/cm2（temperature:200 K,and λ=2050 nm）,10.75 kA/cm2（temperature:200 K,and λ=2000 nm）,and23.12 kA/cm2（temperature:300 K,and λ=2100 nm）,respectively.The results indicate the possibility to obtain a Si-based short-wave infrared Ge1-xSnx laser.

英文摘要：

Optical gain characteristics of Ge1-xSnμx are simulated systematically.With an injection carrier concentration of 5×10^18/cm^3 at room temperature,the maximal optical gain of Ge0.922Sn0.078 alloy（with n-type doping concentration being 5×10^18/cm^3） reaches 500 cm^-1.Moreover,considering the free-carrier absorption effect,we find that there is an optimal injection carrier density to achieve a maximal net optical gain.A double heterostructure Ge0.554Si0.289Sn0.157/Ge0.922Sn0.078/Ge0.554Si0.289Sn0.157 short-wave infrared laser diode is designed to achieve a high injection efficiency and low threshold current density.The simulation values of the device threshold current density Jth are 6.47 kA/cm^2（temperature：200 K,and λ=2050 nm）,10.75 kA/cm^2（temperature：200 K,and λ=2000 nm）,and23.12 kA/cm^2（temperature：300 K,and λ=2100 nm）,respectively.The results indicate the possibility to obtain a Si-based short-wave infrared Ge1-xSnx laser.