Polarization-dependent unidirectional reflectionless in non-Hermitian metasurface and its application in near-field grayscale imaging

Recently, the non-Hermitian optical system draws much attention due to their peculiar optical properties. In this paper, a non-parity-time symmetric muti-layer metasurface is proposed. The polarization-dependent unidirectional reflectionless (UR) effect associated with the exceptional point (EP) is investigated. By adjusting the geometric parameters of the metasurface, the EP based UR phenomenon can be observed at 2360 nm, and the simulation results are in good agreement with the theoretical work. Unlike other isotropic non-Hermitian platforms, the proposed UR phenomenon has a strong dependence on the incident polarization state, which guarantees its great application potential in the fields of near-field imaging and optical encryption, etc.