In view of wide applications of vector light with a non-uniform polarization state, a compound vector light generator is proposed to generate compound vector light. One compound vector light contains two or more non-uniform polarization modes and several annular intensities, which can carry more polarization information and possess higher dimensional singularity. The proposed compound vector light generator consists of cross nanoholes with high polarization conversion efficiency; it works under linear polarized light, and the mode of the generated compound vector light can be adjusted through rotating cross nanoholes. The structure parameters of the compound vector light generator are optimized with the aid of numerical simulation, and the simulation results for the generated light fields verify the performance of the proposed device. The advancement of the compound vector light and metasurface design of the compound vector light generator can assist in the exploration of novel singular properties of light fields and the broadening of applications of vector light fields.

The phase delays introduced by anisotropic nanounits include propagation phase delay, resonant phase delay and geometric phase delay. Various phase devices can be formed based on the metasurfaces consisting of anisotropic nanounits and the phase devices of the same kind function have different performances because of different working modes. In this paper, metalenses and vortex metalenses are chosen as examples to compare the optical performance of metasurface phase devices based on three kinds of phase compensation techniques. We design separately three kinds of metalenses and vortex metalenses using the cross nanoholes, L-shaped nanohole and V-shaped nanoholes and simulate numerically their intensity and phase distributions. Additionally, the results show the differences among these elements in structure complexity, polarization dependence, working efficiency and phase uniformity. The comparison for three kinds of metalenses clearly shows the merits of different phase compensation techniques and this work must be helpful for expanding the practical applications of metasurfaces.

There was an error in the original publication