Experimental Demonstration of Hyperbolic Dispersion in Metasurfaces at Visible Wavelengths

Metamaterials are engineered nanostructured materials having exotic properties which are beyond those observed in conventional materials. Hyperbolic metamaterials, a special class of metamaterials showing hyperbolic dispersion, exhibit some unique optical properties which make them exceptionally suitable for super-resolution imaging using structured illumination microscopy. Hyperbolic metasurfaces, which are the two-dimensional analog of hyperbolic metamaterials, are even more promising due to their negligible propagation loss.

This thesis mainly focuses on the experimental characterization of metasurface samples using the broadband spectroscopic technique. An experimental setup is built in order to characterize the samples in terms of their spectral response. The samples are characterized by changing the length of the ridges, changing the incident angle of the illumination beam, and changing the azimuthal angle of the metasurface samples.

Finally, the results obtained experimentally are compared with those obtained using full-wave effective mode index simulations done using COMSOL multiphysics. The experimental results exhibit a great match for both elliptical and hyperbolic modes obtained using simulations.