Fig. 1. Schematic diagram and experimental results of the polarization converter in reflection. (a) Schematic diagram where p1 and p2 are wire-grid polarizers, one acting as a polarizer to produce x-polarized light and the other as an analyzer to get the y-polarized component of the reflected light, respectively. (b) Optical micrograph of fabricated metamaterial linear polarization converter. (c) Individual element of the high-efficiency linear polarization converter. The incident angle θi=10°, and electric field E0 is linearly polarized in the x direction. All the dimensions are shown, Ax=Ay=40μm, ts=15μm, L=38μm, and W=3μm. The periodic meta-structure units and bottom mirror are made of gold via electron beam evaporation. The dielectric spacer is polyimide film with ε=3.5(1+0.05i). (d) Experimentally measured and numerically simulated co-polarized and cross-polarized reflectance, corresponding to the x and y directions in our experiment, respectively.

Fig. 2. (a) Schematic diagram of u−v coordinate system and the single metasurface layer. (b) Reflection and transmission coefficients extracted from the simulation of a single metasurface layer, tvu=tuv=rvu=ruv=0 in the considered frequency region. (c) The phase φvvt of transmission tvv, which mainly contributes to polarization conversion. The other phases are zeros. (d) The schematic diagram of the F-P-like cavity model for multiple reflections. (e) Theoretical phases with v and u components, which are shown in reflection mode results from the equality of magnitudes of u and v components. (f) Theoretical reflection and transmission amplitudes of cross-polarization and co-polarization.