Low-Temperature Epitaxially Grown GaAs as a High-Speed Photoconductor for Terahertz Spectroscopy,

Abstract : Photoconductive elements have been employed to generate and detect ultrafast electrical signals in many areas of optical electronics. One outstanding application of these structures, when they are fabricated on substrates with rapid recombination times, is as transmitting and receiving antennas that can be used for millimeter-wave and submillimeter-wave spectroscopy. Experiments which characterize a terahertz radiation system using dipole-like antennas have been carried out, and the system has been applied to the spectroscopy of dielectrics and semiconductors. Assuming that short laser pulses and a high quality imaging system are available, the fidelity of the broadcast signals and the resolution attainable for a spectroscopy system depend primarily on the photoconductor material and antenna system.