Figure 3
Frequency-domain characterization of the THz waves enhanced by the antennas. (a) and (b) are the spectral amplitude of each trace for the SBAs and the TBAs (blue gap spot, black reference spot and the magenta transmission spot in the inset of (a)), respectively. (c) and (d) exhibit the ratio of the gap signal to the reference corresponding to (a) and (b), respectively. It should be noticed that the amplitude at zero frequency should be zero in (a). This is caused by noise.
