We report on enhanced third-harmonic generation based on intersubband transitions in an asymmetric In_xGa_1-xN/InN double quantum well. We give a comprehensive account of the influences of different structural parameters such as doping concentration, thickness of layers, and indium mole composition of barriers on the intersubband transition quantities and then their nonlinear response. The conduction band parameters are computed by the numerical solution to Schrödinger and Poisson equations within nonparabolic band approximation. More importantly, the participation of each electron scattering process, e.g., LO phonon scattering in the electron relaxation time and linewidth values, is calculated, so that it can be considered a reference to provide a heterostructure with optimum functionality. Finally, two optimized double quantum wells are designed at the fundamental photon energies of 117 and 144 meV, which exhibit remarkable third-order susceptibility up to $1.2\times {10}^{-3}$ and ${10}^{-3}\mu {\mathrm{m}}^2/{\mathrm{V}}^2$, respectively. This study opens a new path to design a suitable In_xGa_1-xN/InN heterostructure for a third-harmonic generation process from the far- to near-infrared band, which promises various applications in optoelectronic devices.

中文翻译：

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在非对称 InxGa1-xN/InN 双量子阱中高效产生三次谐波

我们报告了基于非对称 In _x Ga _1-x中子带间跃迁的增强三次谐波生成N/InN 双量子阱。我们综合考虑了不同结构参数（如掺杂浓度、层厚度和势垒的铟摩尔组成）对子带间跃迁量及其非线性响应的影响。导带参数是通过非抛物线带近似内的薛定谔方程和泊松方程的数值解来计算的。更重要的是，计算了每个电子散射过程的参与，例如，LO 声子散射在电子弛豫时间和线宽值中的参与，因此可以将其视为提供具有最佳功能的异质结构的参考。最后，在 117 和 144 meV 的基本光子能量下设计了两个优化的双量子阱，$1.2\times {10}^{-3}$ 和 ${10}^{-3}\mu {\mathrm{米}}^2/{\mathrm{伏}}^2$， 分别。这项研究为设计合适的 In _x Ga _1-x N/InN 异质结构开辟了一条新途径，用于从远红外到近红外波段的三次谐波产生过程，有望在光电器件中得到各种应用。