title: Purely coherent nonlinear optical response in solution dispersions of graphene sheets.
abstract: We have developed an efficient chemical exfoliation approach for the high-throughput synthesis of solution-processable, high-quality graphene sheets that are noncovalently functionalized by alkylamine. Purely coherent nonlinear optical response of these graphene sheets has been investigated, using near-infrared, visible, and ultraviolet continous wave and ultrafast laser beams. Spatial self-phase modulation has been unambiguously observed in the solution dispersions. Our results suggest that this coherent light scattering is due to a broadband, ultrafast, and remarkably huge third-order optical nonlinearity χ(3), which is a manifestation of the graphene's cone-shaped large-energy-scale band structure. Our experimental findings endow graphene new potentials in nonlinear optical applications.
authors.affiliation: Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Wu
authors.forename: Yingli
authors.initials: Y
authors.lastname: Zhang
authors.forename: Shichao
authors.initials: S
authors.lastname: Yan
authors.forename: Fei
authors.initials: F
authors.lastname: Bian
authors.forename: Wenlong
authors.initials: W
authors.lastname: Wang
authors.forename: Xuedong
authors.initials: X
authors.lastname: Bai
authors.forename: Xinghua
authors.initials: X
authors.lastname: Lu
authors.forename: Jimin
authors.initials: J
authors.lastname: Zhao
authors.forename: Enge
authors.initials: E
authors.lastname: Wang