Optical communications, laser science, microscopy andmetrology demand control of light polarization, which is alsoused as a probe of chemical and biological systems. Typically,certain polarization states of light are achieved using macroscopicanisotropic crystals. Metamaterials and metasurfaceshave recently been developed to act as efficient passivepolarization components of subwavelength dimensions1–4.However, active polarization control has so far been mainlylimited to microwave and terahertz wavelengths5–7. Here wedemonstrate all-optical switching of visible light polarization,achieving up to 60° rotation of the polarization ellipseat picosecond timescales. This is accomplished both undercontrol illumination and in a self-phase modulation regime,where the intensity of light affects its own polarization state,by exploiting the strong anisotropy and nonlinear response ofa hyperbolic metamaterial3,8–10. The effects are general for anyresonant, anisotropic, nonlinear nanoantennas and metasurfacesand are suited to numerous photonic applications andmaterial characterization techniques where ultrafast polarizationshaping is required.
展开▼
