Polarization-insensitive unidirectional spoof surface plasmon polaritons coupling by gradient metasurface

Shi Hong-yu¹, Zhang An-xue^{1, 2, †,}, Chen Jian-zhong¹, Wang Jia-fu³, Xia Song⁴, Xu Zhuo⁴

Schematic illustration of a normal-polarized field incident onto a gradient metasurface. is the reflective field. The incident plane is the xz plane. The and are the wave vectors of the incident wave in the x and z directions, respectively. The and are the wave vectors of the reflected wave in the x and z directions, respectively.