Nanophotonics: Bright future for hyperbolic chips
Post# of 22456
The unusual properties of hyperbolic metamaterials, such as their ability to propagate light on the nanoscale without diffraction , have been realized in two-dimensional devices, heralding improved photonic circuits. See Letter p.192
http://www.nature.com/nature/journal/v522/n75...2160a.html
Visible-frequency hyperbolic metasurface
Metamaterials are artificial optical media composed of sub-wavelength metallic and dielectric building blocks that feature optical phenomena not present in naturally occurring materials1, 2, 3, 4, 5, 6, 7. Although they can serve as the basis for unique optical devices that mould the flow of light in unconventional ways, three-dimensional metamaterials suffer from extreme propagation losses8, 9. Two-dimensional metamaterials (metasurfaces) such as hyperbolic metasurfaces for propagating surface plasmon polaritons10, 11 have the potential to alleviate this problem. Because the surface plasmon polaritons are guided at a metal–dielectric interface (rather than passing through metallic components), these hyperbolic metasurfaces have been predicted to suffer much lower propagation loss while still exhibiting optical phenomena akin to those in three-dimensional metamaterials. Moreover, because of their planar nature, these devices enable the construction of integrated metamaterial circuits as well as easy coupling with other optoelectronic elements. Here we report the experimental realization of a visible-frequency hyperbolic metasurface using single-crystal silver nanostructures defined by lithographic and etching techniques. The resulting devices display the characteristic properties of metamaterials, such as negative refraction1, 2, 3, 4, 5 and diffraction-free propagation6, 7, with device performance greatly exceeding those of previous demonstrations. Moreover, hyperbolic metasurfaces exhibit strong, dispersion-dependent spin–orbit coupling, enabling polarization- and wavelength-dependent routeing of surface plasmon polaritons and two-dimensional chiral optical components12, 13, 14, 15. These results open the door to realizing integrated optical meta-circuits, with wide-ranging applications in areas from imaging and sensing to quantum optics and quantum information science.
http://www.nature.com/nature/journal/v522/n75...14477.html