3D printed cross-shaped terahertz metamaterials with single-band, multi-band and broadband absorption

Abstract

Terahertz metamaterial absorbers (THz MAs) have attracted significant attention for their unprecedented ability to modulate the incident terahertz wave effectively. Prevalent manufacturing of THz MAs has been mainly restricted by the traditional micro-nano fabrication technique due to their micro-scale characteristic size of the unit cell. However, conventional fabrication technique has been suffered by the involvement of multi-step and time-consuming processes as well as expensive facilities. To overcome these bottlenecks, we have proposed a novel and efficient fabrication technique based on the projection micro-stereolithography 3D printing followed by the electron beam evaporation coating to manufacture the THz MAs additively. A typical cross-shaped MA is taken into account as the prototype to demonstrate the effectiveness of the proposed technique. A broadband and a triple-band MA are then realized by combining four cross-shaped resonators and the alternative of the cross-shaped resonator. Both experimental measurements and theoretical simulation exhibit the expected absorption performance of three types of 3D printed MA samples in the THz band. It can be estimated that the proposed 3D printed technique provides a simple but universal fabrication approach for the THz MAs and paves the avenue toward its foreseeable applications on the versatile design and manufacturing of functional THz devices.