Quasi-phase matching (QPM) enables flexible and efficient second-order nonlinearity ranging from bulk nonlinear crystals to integrated nonlinear photonic devices. Here, we propose a QPM nonlinear photonic device constructed using monolayer transition-metal dichalcogenide (TMDC) arrays attached on a silicon nitride waveguide. QPM second harmonic generation comes from a nonlinear interaction between evanescent fields of fundamental-frequency and second-harmonic guided modes with periodical monolayer TMDC arrays. Dispersions of the device can be tuned by changing the geometric parameters of the waveguide while the nonlinear overlap integral and the QPM condition can be controlled through the distribution of TMDC arrays. Our design provides a practical way to efficiently shape second-order nonlinearities in complementary metal–oxide–semiconductor-compatible photonic platforms.

准相位匹配 (QPM) 可实现灵活且高效的二阶非线性，范围从大块非线性晶体到集成非线性光子器件。在这里，我们提出了一种使用连接在氮化硅波导上的单层过渡金属二硫属化物 (TMDC) 阵列构造的 QPM 非线性光子器件。QPM 二次谐波产生来自基频和二次谐波导模的渐逝场与周期性单层 TMDC 阵列之间的非线性相互作用。器件的色散可以通过改变波导的几何参数来调整，而非线性重叠积分和 QPM 条件可以通过 TMDC 阵列的分布来控制。