Ultrathin and Ultra‐Broadband Terahertz Single‐Layer Metasurface Based on Double‐Arrow‐Shaped Resonator Structure for Full‐Space Wavefront Manipulation.

In this paper, a simple design of an ultrathin and ultra‐broadband single‐layer MS based on double‐arrow‐shaped resonator (DASR) structure for both transmission and reflection modes in terahertz (THz) region is presented. The single‐layer MS is composed of a periodic array of the combination of the metal DASR and complementary circular patch (CCP) adhered on an ultrathin dielectric substrate. Numerical results show that the MS structure can convert CP wave to its orthogonal component after reflection and transmission simultaneously, and the corresponding amplitudes are ≈0.45 on average from 0.45 to 1.75 THz with a relative bandwidth of 118.2%, in which the CP conversion efficiency is closing to theoretical limit (25%) of the single‐layer structure. Furthermore, the 0–2π phase shifts for the reflected and transmitted orthogonal CP wave can be achieved simultaneously by adjusting the oriented angle (α) of the DASR structure along the wave propagation direction. For the concept proofs, wave beams deflection, vortex beam generation, and focusing effect for both reflection and transmission modes are demonstrated numerically. The design can provide new possibilities and potential to develop multifunctional full‐space devices. [ABSTRACT FROM AUTHOR]