A multi-band spoof surface plasmon polariton coupling metasurface based on dispersion engineering

We propose a metasurface to achieve multi-band helicity dependent directional spoof surface plasmon polaritons (SPPs) coupling for circular polarized light in the microwave range. Our work shows that the coupling frequencies of spoof SPPs on the gradient metasurface are related to the dispersion relations of the metasurface, which indicate the desired coupling frequency can be manipulated by dispersion engineering. The proposed metasurface has counter-directional phase gradients for different helicity incidents and possesses multiple different dispersion relations by carefully designing the geometric parameters of each unit, which leads to the multi-band helicity-controlled directional spoof SPPs coupling. Both the simulation and experiment show that the multi-band helicity-controlled directional spoof SPPs coupling is achieved with a high efficiency.