▎ 摘　　要

With the rapid development of nanofabrication technology and nonlinear optics, the nonlinear detection by nanostructures is highly appreciated. In this paper, we study the second-harmonic generation by a spherical nonlocal plasmonic nanoparticle wrapped with graphene. We develop a simple method tbr calculating the electric field at second-harmonic frequency and analyze the influence of the nonlocal response of the metal on the second-harmonic. We find that this nanostructure can probe the material's properties by detecting the radiation intensity of the second-harmonic generation. In addition, the nonlocal response of the plasmonic core can promote the absorption efficiency of second-harmonic generation. Our study may offer a new way for studying the plasmonic quantum effects and nonlinear probing technology and improving the nonlinear conversion efficiency of photonic devices. (C) 2022 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement