Quasi-phase matching (QPM) is a well-known technique to improve the efficiency of frequency conversion processes in 3D nonlinear optical materials. Here, the authors report the implementation of nanoscale QPM in 2D 3R-stacked twisted MoS2, showing enhanced second harmonic generation and spontaneous parametric down-conversion.
- Yilin Tang
- Kabilan Sripathy
- Yuerui Lu