Metasurface-loaded waveguide for transformation optics applications. (1st April 2016) - Wei, Pengjiang
Abstract: We theoretically investigate a two-dimensional metasurface-loaded waveguide as a generic platform for transformation optics (TO) applications. The mode indices can achieve values much less or greater than one by tuning the reflection phase from the metasurface. Due to the subwavelength feature size of the metasurface, we develop an effective description of the wave propagation using an artificial electromagnetic boundary approach, which replaces the effective medium description of TO for bulk media. We numerically demonstrate a constant zero-index medium for wave collimation, gradient index profiles as Luneburg and Maxwell fisheye lenses and a wave bender based on the finite embedded coordinate transformation. These investigations provide a feasible route to perform TO with metasurfaces as waveguide boundaries, yet the designs can still be obtained using an effective boundary approach with only a few constitutive parameters.