polarization

pet ct

patients ra

mortality_69498

polarization conversion

terahertz_111451

wavefront

circularly

motion planning

po sub

bacterial_57212

metasurface_24723

metasurface_24731

dual-band

iliac artery

optical information

dogs_37752

psychological state

functionalities

Opto-Electronic Science

Metasurfaces that can realize the polarization manipulation of electromagnetic waves on the sub-wavelength scale have become an emerging research field. Here, a novel strategy of combining the metasurface and Fresnel zone plate to form a metasurface zone plate is proposed to realize the conversion from nearly arbitrary polarizations to a fixed polarization. Specifically, when one polarized wave is incident on adjacent ring zones constructed by different types of meta-atoms, the transmitted waves generated by odd-numbered and even-numbered ring zones converge at the same focus and superimpose to generate a fixed polarized wave. As function demonstrations, we have designed two types of metasurface zone plates: one is a focused linear polarizer, and the other can convert nearly arbitrary polarized waves into focused circularly polarized waves. The simulated and measured results are consistent with theoretical expectations, suggesting that the proposed concept is flexible and feasible. Our work provides an alternative platform for polarization manipulation and may vigorously promote the development of polarization photonic devices.

Terahertz metasurface zone plates with arbitrary polarizations to a fixed polarization conversion