Unidirectional Propagation of Surface Plasmon Polaritons Based on Black Phosphorus

Manipulating electromagnetic wave properties through the microstructure design of metamaterials is a sought-after goal for nanophotonics and integrated photonics. Hyperbolic metamaterials can produce strongly confined light propagation at deep-subwavelength scales and can support high-k modes, demonstrating great potential in near-field optical manipulation. As a natural hyperbolic material, black phosphorus has strong in-plane anisotropy and shows rich dispersion characteristics in the infrared band. In this work, we analyze the dispersion characteristics of black phosphorus materials and find a rich dispersion topology. In addition, a surface plasmon polaritons propagating unidirectionally on black phosphorus was found, we can simply control the highly restricted propagation of SPP in the selected direction. This design method based on hyperbolic material opens new routes to realize surface plasmon polaritons manipulation.