Generation of coherent terahertz radiation by photomixing in dipole photoconductive antennas

Abstract

We demonstrate the generation of continuous-wave terahertz radiation at frequencies up to 3.5 THz by photomixing in LT-GaAs photoconductors with printed dipole antennas. The expected resonance peak was clearly observed in the radiation spectrum of a 50 μm dipole antenna, and the radiation property was discussed in terms of the antenna impedance. The spectral bandwidth was greater than the electrical bandwidth of the photoconductor determined by the carrier lifetime of the material. The quality of the resonance, however, was not as high as expected because of the imperfect geometry and ohmic loss of the antenna.