▎ 摘　　要

In this work, nonlinear optical response of the graphene oxide and an ionic liquid immobilized on a magnetic graphene oxide composite (IMIP-MGO) was investigated experimentally by open and close aperture of Z-scan technique. Magnetic graphene oxide was synthesized during the in situ formation of magnetite nanoparticles in an aqueous emulsion of graphene oxide and it was physically functionalized with the ionic liquids. We observed that the prepared sample has a giant nonlinear refractive index and nonlinear absorption coefficient in comparison with bare graphene oxide. The prepared sample was utilized for the optical limiting application at the low power of visible range spectrum of laser beam at the wavelength of 532 nm. Our experimental results show that the IMIP-MGO has the suitable limiting properties for low power of CW laser beam with the optical limiting threshold value of 30 mw.