All-dielectric terahertz metalens using 3D-printing

Terahertz (THz) electromagnetic waves offer a new way of understanding various phenomena, owing to their non-ionizing properties resulting from their low energy, and non-destructive inspection features in dielectrics. Although THz emitters and detectors have been developed with much interest, the performance of optics in the THz band is still limited by the properties of the available materials. Metamaterials, which are the artificial subwavelength structures for implementing optical properties that do not exist in intrinsic materials, proposed as a new approach. However, their fabrication requires a complex semiconductor manufacturing process for its elaborate structure. In this study, we demonstrated the fabrication of all-dielectric THz metamaterial optics using an accessible 3D printing technology. A meta-element consisting of a square pillar exhibited full-wave phase controllability. The metalens was designed for 0.2 THz. The metalens fabricated using a low-cost LCD-type 3D printer and photopolymer resin showed good focusing performance and polarization insensitivity.