H-type Photoconductive Antennas Manipulated by Nano- And Micron-Scale Meta-Atoms

Here we proposed and demonstrated two meta-atoms assisted H-type photoconductive antennas (PCAs) with novel features. The first one has all-dielectric nanopillars in the PCA gap which substantially enhance the absorption of the femtosecond laser pump, and thus realize a 1.94-fold increase on the emitted THz amplitude. The second PCA employs micron-scale metallic split-ring resonators (SRRs) to manipulate the terahertz wave propagating in the coplanar transmission lines, which can manipulate the spectrum of the far-field terahertz field. The reported results may extend and deepen the studies on metamaterial assisted PCAs.