In Situ Third-Order Nonlinear Responses During Laser Reduction of Graphene Oxide Thin Films Towards On-Chip Nonlinear Photonic Devices

摘要

Graphene oxide (GO) has become a rising star in the graphene family owing to its unique physical and chemical properties originated from the hybridization of the sp~2- and sp~3- carbon atoms. One of the most intriguing and unique properties of GO is that its electrical and optical properties can be tuned dynamically by manipulating the content of oxygen-containing groups through either chemical or physical reduction methods. In particular, recently the maskless direct laser writing (DLW) method has been proved to be powerful in inducing both the localized reduction and the controllable patterning of functional optoelectronic devices on a GO film in a single step, opening enormous potential in producing high quality integrated photonic components directly on a solid state thin film. Through controlling the applied laser energy doses, three fundamental physical parameters of the GO films can be tuned continuously by manipulating the oxygen level, which are the conductivity, bandgap and refractive index. Owing to the ease of the device fabrication as well as the tun-ability of the fundamental parameters, GO films provide a new revenue for functional device design and can lead to a new surge of the conceptual development for integrated optoelectronics and photonics.