We propose and design a nonlinear-polymer-filled asymmetric silicon slot waveguide (SSW) for efficient second-harmonic generation. The distinct modal dispersion of the designed asymmetric SSW is used to achieve phase matching between the zeroth-order waveguide mode at the fundamental frequency ($\lambda = {3.1}\,\,\unicode{x00B5}{\rm m}$) and the second-order mode at the second-harmonic frequency ($\lambda = {1.55}\,\,\unicode{x00B5}{\rm m}$). Simulation results show a conversion efficiency of ${P_{2\omega }}/{P_\omega } = {32}\% $ with only 10 mW pump power. This high efficiency is a consequence of introducing an asymmetry in the SSW which not only could provide modal phase matching but also preserves high modal overlap between the interacting waves and leads to relatively low propagation loss. The proposed structure, which is well realizable with current CMOS technology, allows extra tuning by the electro-optic effect for eliminating phase mismatch resulting from fabrication errors.

中文翻译：

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基于模态相位匹配的二次谐波非对称硅聚合物混合波导

我们提出并设计了一种非线性聚合物填充的不对称硅缝隙波导（SSW），以有效地产生第二谐波。设计的非对称SSW的独特模态色散用于​​在基本频率（$ \ lambda = {3.1} \，\，\ unicode {x00B5} {\ rm m} $）处实现零阶波导模式之间的相位匹配。以及在第二谐波频率下的二阶模式（$ \ lambda = {1.55} \，\，\ unicode {x00B5} {\ rm m} $）。仿真结果表明，转换效率为$ {P_ {2 \ omega}} / {P_ \ omega} = {32} \％$仅10 mW的泵浦功率。这种高效率是在SSW中引入不对称性的结果，它不仅可以提供模态相位匹配，而且可以保持相互作用波之间的高模态重叠，并导致相对较低的传播损耗。所提出的结构可以利用当前的CMOS技术很好地实现，并允许通过电光效应进行额外的调整，以消除由制造误差引起的相位失配。