Nonlinear graphene metamaterial
  We demonstrate that the broadband nonlinear optical response of graphene can be resonantly enhanced by more than an order of magnitude through hybridization with a plasmonic metamaterial,while retaining an ultrafast nonlinear response time of ~1 ps. Transmission modulation close to ~1% is seen at a pump uence of ~0.03 mJ/cm^2 at the wavelength of ~1600 nm. This approach allows to engineer and enhance graphene's nonlinearity within a broad wavelength range enabling applications in optical switching, mode-locking and pulse shaping. 
Andrey E. Nikolaenko, Nikitas Papasimakis, Evangelos Atmatzakis,   Zhiqiang Luo, Ze Xiang Shen, Francesco De Angelis, Stuart...
physics.optics