Infrared hyperbolic metasurface based on nanostructured van der Waals materials

Metasurfaces with strongly anisotropic optical properties can support deep subwavelength-scale confined electromagnetic waves (polaritons), which promise opportunities for controlling light in photonic and optoelectronic applications. We developed a mid-infrared hyperbolic metasurface by nanostructuring a thin layer of hexagonal boron nitride that supports deep subwavelength-scale phonon polaritons that propagate with in-plane hyperbolic dispersion. By applying an infrared nanoimaging technique, we visualize the concave (anomalous) wavefronts of a diverging polariton beam, which represent a landmark feature of hyperbolic polaritons. The results illustrate how near-field microscopy can be applied to reveal the exotic wavefronts of polaritons in anisotropic materials and demonstrate that nanostructured van der Waals materials can form a highly variable and compact platform for hyperbolic infrared metasurface devices and circuits.

Source: ScienceNOW - February 22, 2018 Category: Science Authors: Li, P., Dolado, I., Alfaro-Mozaz, F. J., Casanova, F., Hueso, L. E., Liu, S., Edgar, J. H., Nikitin, A. Y., Velez, S., Hillenbrand, R. Tags: Physics, Applied, Physics reports Source Type: news