Theoretical study on generation of radially polarized beam from linearly polarized beam with all-silicon metasurface in the terahertz regime

作者：Wang, Zewen^*; Li, Qi; Yan, Fei

来源：Optics and Laser Technology, 2021, 136: 106763.

DOI：10.1016/j.optlastec.2020.106763

• Transmissive all-silicon metasurface
• Errors analysis
• Polarization conversion
• Terahertz beam shaping

A transmissive all-silicon dielectric square metasurface with a side length of 12.4 mm is designed in this paper. At 2.52 terahertz, the normally incident x-polarized Gaussian beam can be shaped into the radially polarized narrow-width annular beam with Bessel-Gaussian amplitude distribution at a propagation distance of 45 mm away from the metasurface. Anisotropic rectangular silicon pillars with different dimensions and rotation angles are arranged on the silicon substrate to manipulate the beam. To suppress the reflection loss, a polarization-independent square silicon pillar array is also proposed, which is patterned at the other side of the substrate. In addition, the errors analysis is also discussed. It is expected that our study may have potential for applying terahertz wave in high-resolution microscopy and capturing particles in three dimensions.

• 单位
  harbin inst technol