Progress in Physics
Optimizing the generation of second harmonic optical vortices from nonlinear photonic crystals 
LIU Shiqiang , ZHANG Xinyu, CHEN Yan, LI Shifeng, ZHAO Gang, ZHU Shining , HU Xiaopeng
Progress in Physics . 2025, (4): 191 -168 .  DOI: 10.13725/j.cnki.pip.2025.04.001