Benefiting from the unprecedented capability of metasurfaces in the manipulation of light propagation, metalenses can provide novel functions that are very challenging or impossible to achieve with conventional lenses. Here, an approach to realizing multi‐foci metalenses is proposed and experimentally demonstrated with polarization‐rotated focal points based on geometric metasurfaces. Multi‐foci metalenses with various polarization rotation directions are developed using silicon pillars with spatially variant orientations. The focusing characteristic and longitudinal polarization‐dependent imaging capability are demonstrated upon the illumination of a linearly polarized light beam. The uniqueness of this multi‐foci metalens with polarization‐rotated focal points may open a new avenue for imaging, sensing, and information processing.

Electromagnetic waves carrying orbital angular momentum (OAM), namely, vortex beams, have a plethora of applications ranging from rotating microparticles to high‐capacity data transmissions, and it is a continuing trend in manipulating OAM with higher degrees of freedom. Here, an approach to control terahertz (THz) near‐field plasmonic vortex based on geometric and dynamic phase is proposed and experimentally demonstrated. By locally tailoring the orientation angle (geometric phase) and radial position (dynamic phase) of aperture arrays embedded in an ultrathin gold film, the excited surface waves can be flexibly engineered to form both spin‐independent and spin‐dependent THz plasmonic vortex field distributions, resulting in multi‐degree of freedom for controlling OAM of THz surface plasmon polaritons (SPPs). Arbitrary OAM values of THz plasmonic vortex and coherent superposition between two OAM states are investigated based on near‐field scanning terahertz microscopy (NSTM) system. The proposed approach provides unprecedented freedom to modulate THz near‐field plasmonic vortex, which will have potential applications in THz communications and quantum information processing.

Driven by system integration and device miniaturization, a single device with multiple functions is desirable. In article number 1900182, Xianzhong Chen, Yiming Zhu, and co‐workers demonstrate a metalens that can focus the incident THz waves into two focal spots with predesigned polarization rotation. This approach not only provides a platform for multiplexing of focusing and polarization rotation, but also opens a novel avenue for polarization‐dependent imaging.

No abstract