Generation of tunable narrow-band THz radiation from large aperture photoconducting antennas

Abstract
We report a novel technique for the generation of tunable narrow-band submillimeter wave electromagnetic radiation in free space. This is accomplished by mixing two linearly chirped optical pulses with a variable time delay on a biased large aperture GaAs photoconducting antenna. The center frequency of the THz radiation varies linearly with the delay between the two chirped pulses from dc to ∼1 THz.