Tunable Nonlinearity in 2D Graphdiyne Oxide for High-Performance All-Optical Modulation

2D atomically thin graphdiyne oxide (GDYO) nanosheets (NSs) are synthesized, and their nonlinear modulation is investigated. Generally, improving the modulation depth (MD) of all-optical modulation (AOM) requires a pump light with strong power, which limits the development of AOM technology in the design of low-power loss devices. In this study, an AOM system based on spatial self-phase modulation and spatial cross-phase modulation methods is proposed using 2D GDYO NSs. The results reveal that 2D GDYO exhibits tunable nonlinearity and high stability, which is desirable for designing the AOM system. Because of the excellent optical properties of 2D GDYO, a large MD of >98% is achieved for the proposed AOM with a low power of pump light, which is higher than most AOMs currently reported. Thus, GDYO is an excellent modulation material in AOM, which improves the application prospects of carbon nanomaterials in all-optical devices.