基于多模速率方程电路建模的太赫兹量子级联激光器稳态性能及输出光谱特性分析

通过改进的三能级多模态速率方程,运用电路建模 方法,建立了太赫兹(THz)量子级联激光器(QCL)的一种等效电路模型。由于基于多模 态效应进行建模,所建模型能够有效表 征多模态效应对THz QCL光电性能的影响。模型中,涉及的非辐射散射时间、自激发射弛豫 时间以及电子逃 逸时间均根据器件有源层结构参数通过自洽数值求解获得。采用所建模型,可运用通用电路 仿真工具实现对 THz QCL光电特性的模拟分析,克服了数值分析方法计算复杂、模拟时间长的缺点。运用电 路仿 真工具PSPICE对2.47THz QCL的稳态特性和输出光谱特性进行了模拟 分析,并讨论了温度变化对器 件阈值电流、输出光功率以及输出频谱的影响,分析结果与已报道的理论和实验结果一致 ,验证了本文方法的适用性和准确性。

Steady state responses and optical spectra simulation for THz quantum cascaded l asers based on a circuit-level model of multi-mode rate equation

In this paper,an equivalent circuit model for terahertz quantum cascade lasers ( THz QCLs) is introduced by virtue of revised three-level multi-mode rate equations.This mod el accounts for influence of multi-mode on steady and optical spectra characteristics of THz QCLs.Both the p hoton gain coefficient and the spontaneous emission coupling coefficient depend on the wavelength in this model .The nonradiative scattering times,radiative spontaneous relaxation time and electron escape time are obtain ed by a self-consistent scheme. The model enables the analysis of the steady and optical spectra characteristics of THz QCL using general circuit analysis software,which overcomes the shortcomings of complexity and long simula tion time of numerical analysis method.Based on this new model,the steady and optical spectra charact eristics of a 2.47THz device with lattice temperature of 5K and 78K are investigated by using a circuit simula tor PSPICE.Results indicate that the model is practical and accurate for THz QCL simulation studies.