Planar Bowtie Nanoarray for THz Energy Detection

In this paper, an investigation is presented into nanogap-based bowtie nanoarrays for THz energy detection, with the aim of optimizing their geometrical parameters utilizing finite-element method (FEM) based simulations. The bowtie elements of the array are connected by feeding lines, which are used to transfer the captured electric field away from the antenna´s center to a common feeding gap. The performance of the bowtie nanoarray has been compared with a single bowtie element constructed using the same device area. The obtained results demonstrated that the array outperforms the single element bowtie. Subsequently, a parametric study is carried out on important geometrical parameters of the array to optimize its performance. The results demonstrate that the optimum spacing between array elements is 2.9 m, whereas the best line width of the feeding lines is 50 nm. Additionally, it has been found that a 25 nm gap offers the highest electric field at resonance. Furthermore, a bowtie nanoarray is designed based on the optimized parameters of the parametric study. Finally, the effects of the incident angle and curvature of the edges of the array elements and feeding lines have also been studied and their impact on the overall performance is presented in this paper.