Mazur, L. M.Liu, S.Krolikowski, W.Sheng, Y.2026-01-012026-01-019781943580798https://hdl.handle.net/1885/733798917We extend functionality of nonlinear photonic crystal by fabricating curved fork-like spatial modulation of nonlinearity for generation of second harmonic “perfect vortices”. Their diameter remains constant independently of their topological charge.This work was supported by the Qatar National Research Fund (grant NPRP12S-0205-190047) and the Australian Research Council.enPublisher Copyright: © 2020 The Author(s)202085095437339