Multi-foci metalens based on all-dielectric metasurface with simultaneous amplitude and phase modulation

Abstract

Abstract Metasurfaces provide a novel platform for designing high efficiency and multi-functional photonic devices with compact size. Multi-foci metalens have great potential in the applications of optical tomography technology, optical data storage, optical communication and photoelectric detection. Here, in order to broaden the functionality and applicability of multi-foci metalens, a scheme for designing multi-foci metalens based on all-dielectric metasurface with simultaneous amplitude and phase modulation is demonstrated. Based on this, a linear-polarization-dependent multi-foci metalens which can focus x-polarization and y-polarization incident wave into multiple focal points independently is designed and demonstrated numerically, the intensity ratio between the x-polarization foci and y-polarization foci can be tuned continuously by varying the polarization angle of incident wave. In addition, the polarization-independent multi-foci metalens and dual-frequency multi-foci metalens have also been demonstrated by utilizing this method, the intensity ratio among these foci can be designed at will. This work is of great significance for the practical applications of multi-foci metalens.