▎ 摘　　要

We have obtained reduced graphene oxide (rGO) by reducing the graphene oxide (GO) polymer using a femtosecond (fs) pulse laser. A method for the fabrication and preparation of GO-polymer composite is first described. We then discuss the reduction of GO-polymer to rGO using direct laser writing technology. We have characterized a fabricated rGO binary phase grating and shown that the degree of the photoreduction of GO-polymer to rGO-polymer can be controlled by the laser power. Phase modulation has been found to be more than 2 pi/3. Finally, we have designed a computer-generated hologram to realize an rGO fork grating. Upon illumination of the grating, a vortex beam is generated through diffraction. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement