太赫兹量子级联激光器有源区有限元模拟

Finite Element Simulation of the Active Region in Terahertz Quantum Cascade Lasers

采用有限元分析法解决了太赫兹量子级联激光器(THz QCL)有源区模拟问题。由于InP基差频THz QCL有源区为千层纳米结构,无法拆分实验探索,因此模拟分析显得尤为必要。首先列出有源区量子结构的薛定谔方程,而后采用Galerkin有限元法改写薛定谔方程,再根据连续性和边界条件,得到本征值矩阵方程,最后采用Matlab写出运算程序求解本征值矩阵方程,求出波函数。针对不同有源区量子结构,设定材料、组分、厚度和周期数及外加偏压等参数,即可得到波函数模方、能级、频率和波长等模拟结果。选取InP基差频THz QCL结构进行验证,结果表明此模型切实可行,其拓展应用也可以解决GaAs THz QCL模拟问题。

The simulation problem about the active region of terahertz quantum cascade lasers（THz QCLs） was solved by the finite element analysis method.The simulation analysis is necessary because the thousand-layer nanostructure for the active region of InP-based difference-frequency THz QCLs cannot be resolved experimentally.Firstly,the Schrdinger equation of active region quantum semiconductor structures was presented,and it was rewritten with the Galerkin finite element method.Then,the eigenva-lue matrix equation was obtained according to the continuity and boundary conditions.Finally,the operation program was compiled to compute eigenvalue matrix equation and evaluate the wave function by Matlab.According to different active region quantum structures,the simulation results including the wave function norm,energy level,frequency and wavelength were obtained instantly through setting the correlative parameters,such as materials,composition,thickness,periodicity and bias voltage.The validation of InP-based difference-frequency THz QCL structure was carried out.And the results indicate that the model is feasible,and its application field can be extended to solve the simulation problem of GaAs THz QCLs.