Near-perfect conversion of a propagating plane wave into a surface wave using metasurfaces

Conversion between free-space and guided-wave propagation modes is an essential function in numerous microwave, optical, and acoustical devices. The performance of currently available wave couplers is far from perfect due to the presence of parasitic scattering and reflections, which have been considered unavoidable up till now. The authors propose a technique for converting a homogeneous plane wave into a surface wave with linear power growth using metasurfaces. With a dramatic enhancement of conversion efficiency, the proposed metasurface wave couplers will find numerous applications ranging from perfect leaky-wave antennas in the microwave range to ideal photovoltaic cells in the visible range.