Metasurfaces, composed of an array of subwavelength artificial structures, have attracted great interest, owing to their high ability in locally manipulating the wavefront of electromagnetic waves. Here, we propose a dielectric metasurface based on a fused silica resonator, consisting of a rectangular-shaped bar placed in the center of a cross net-shaped structure, to manipulate the wavefront of terahertz waves. As proof of concept, several transmission-type devices for spatial modulation are designed at the target frequency of 0.14 THz, including on-axis and off-axis focusing, generation of a non-diffracting Bessel beam, and multi-focus lens. The simulated efficiencies range from 45 to 62%. This novel approach for manipulating THz wavefronts can be also used for information storage and other phase-related techniques in the rapid development of THz applications.

由亚波长人造结构阵列组成的超颖表面由于其在局部操纵电磁波波前的高能力而引起了极大的兴趣。在这里，我们提出了一种基于熔融石英谐振器的介电超表面，该介电超表面由放置在十字网状结构中心的矩形棒组成，以操纵太赫兹波的波前。作为概念验证，在0.14 THz的目标频率上设计了几种用于空间调制的透射型设备，包括轴上和轴外聚焦，非衍射贝塞尔光束的产生以及多焦点透镜。模拟效率范围为45％至62％。