All-Optical Graphene Oxide Modulator Based on Phase-Shifted FBG

An all-optical graphene oxide modulator based on phase-shifted FBG is proposed and experimentally proved to overcome the electronic bottleneck. The phase-shifted FBG is formed by tapering and the surface of nanofiber is covered with graphene oxide film to adjust the phase-shift. In order to reduce the complexity of production and improve the practicability, graphene oxide aqueous solution is used to produce the film on the surface of nanofiber. Experimental results show that the graphene oxide can obtain different phase shifts in phase-shifted FBG by changing the pump intensity. The extinction ratio of the proposed modulator can reach up to 1.1 dB. Besides, the experimental result of transmission spectrum is consistent with the simulated result. With its narrow band-stop characteristics, multiple modulators can be cascaded to achieve the wavelength division, which takes full advantage of low-loss. Due to the ultra-fast and broadband response of graphene, the theoretical rate of the modulator can reach 200 GHz. Therefore, the modulator has broad applications in ultra-high-speed all-optical networks.