Abstract
Two dimensional terahertz metamaterials, which are split-ring resonators and closed-ring resonators, are
printed on high-resistivity silicon substrates by super-fine ink-jet printing. The printed samples show
band-reject responses that are originated from the resonances of the meta-atoms. By loading the metaatoms
to photoconductive antennas, optical switching of the spectrum and polarization of terahertz
radiation has been demonstrated. The switching is based on the sensitivity of the resonance of a splitring
resonator on a photoconductive substrate to a change in the capacitance induced by optical pulse
irradiation. The spectral and polarization characteristics of the split-ring resonator-loaded
photoconductive antennas are reasonably explained by the coupling between the electric dipole induced
by the pump laser and the resonances of the split-ring resonators.
