Fig. 1. Polarization conversion under different polarized incidences. (a) Schematic of a metasurface with polarized conversion, which converts the LP waves or CP waves into specific EP waves and focuses on one point, simultaneously. (b) Schematic of the proposed polarizer that can realize the function of mutual polarization conversion between linear polarization and circular polarization by a design based on an all-silicon metasurface.

Fig. 2. (a) Schematic of the all-silicon pillars. (b)–(e) Schematic of the corresponding phase shifts and amplitudes under x-LP (y-LP) incidence at 0.95 THz. (f) Simulated phase delays of the transmitted x and y components of six meta-atoms A in (a). (g) Simulated amplitudes under LCP (RCP) incidences.

Fig. 3. Transmission characteristics of the proposed metasurface. (a)–(d) The intensity distributions of the desired EP wave and its orthogonally polarized wave on the focal plane under CP or LP illumination.

Fig. 4. (a) Simulated phase delays along the x and y components in the transmission direction. (b) Structure image of the polarization multiplexed metasurface. (c), (d) Simulated intensity profiles of EP waves generated by meta-atoms A and B on the xoz plane. (e) Simulated results of polarized waves on the focal plane 4.8 mm away from the metasurface under RCP incidence.

Fig. 5. (a)–(c) Intensity profiles of the desired polarization and the corresponding orthogonal polarization in the cases of LCP, x-LP, and y-LP incidences.