Abstract

The temporal spectroscopic behavior of the terahertz (THz) single pulse, which transmitted through the metal hole array, has been investigated using the short-time Fourier transform (Gabor transform). In the Gabor spectrum, it is observed that the THz wave at the resonant frequency of the surface plasmon-polariton (SPP) is delayed for several picoseconds with compared to that at other frequencies higher than the diffraction frequency. Since such delay time depends on the thickness of the metal slab, it is concluded that the delay at the SPP resonant frequency is attributed to the decrease of the group velocity of the THz wave inside the metal hole.

© 2004 Optical Society of America