Enhanced optical nonlinearity in noncovalently functionalized amphiphilic graphene composites

The good solubility of graphene-based materials in various solvents without sacrificing their intrinsic properties is a prerequisite for their further applications. In particular, it is important for application as a practical optical limiter. A comprehensive study was conducted on the nonlinear optical property of a rationally designed amphiphilic graphene composite (PEG-OPErGO). By taking advantages of the unique energy diagram of this graphene composite, the optical limiting (OL) performances of PEG-OPE-rGO, which is either dissolved in solvents with moderate polarity or fabricated into thin solid films, are beyond the reported results for other graphene composites. Importantly, the main factors for the enhanced OL response of PEG-OPE-rGO are the multiphoton absorption and Fçrster resonance energy transfer process, instead of the nonlinear scattering mechanism observed for common nanostructured materials. The excellent OL response of PEG-OPE-rGO allows it to be one of the best candidates in practical optical limiters. Moreover, the mechanism analysis provides the deep insight for further optimization of the design of promising OL materials.