In this work we investigate a structure based on p-doped Ge/SiGe asymmetric-coupled quantum wells (ACQW) that enables the second harmonic generation in SiGe waveguide by double-resonant intersubband transitions (ISBTs). These transitions lead to χ coefficients in the range 10-10 pm/V, significantly higher compared to the one of conventional nonlinear materials. We developed a model for the integration of Quantum Wells (QWs) into the active region of the waveguide through an adiabatic taper. Furthermore, we modelled the second harmonic (SH) conversion efficiency as a function of the propagation length, under both non-phase matching and phase-matching conditions. Our work demonstrates that the SiGe ACQWs can be used in spectral ranges not covered by the majority of conventional non-linear crystals, while allowing for the ready-integration with the CMOS technologies.

中文翻译：

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p型Ge/SiGe量子阱中的中红外二次谐波产生：走向波导集成

在这项工作中，我们研究了一种基于 p 掺杂 Ge/SiGe 不对称耦合量子阱 (ACQW) 的结构，该结构能够通过双谐振子带间跃迁 (ISBT) 在 SiGe 波导中产生二次谐波。这些转变导致 χ 系数在 10-10 pm/V 范围内，明显高于传统非线性材料的系数。我们开发了一种模型，用于通过绝热锥度将量子阱 (QW) 集成到波导的有源区域中。此外，我们在非相位匹配和相位匹配条件下将二次谐波 (SH) 转换效率建模为传播长度的函数。我们的工作表明，SiGe ACQW 可以用于大多数传统非线性晶体未涵盖的光谱范围，同时允许与 CMOS 技术集成。