Generation of megawatt-power terahertz pulses by noncollinear difference-frequency mixing in GaAs

Abstract

Terahertz pulses with a peak power of ∼2MW were generated in a noncollinear phase-matched GaAs crystal at room temperature. Efficient difference-frequency generation was achieved using 250-ps CO2 laser pulses for which the surface damage threshold increased in comparison with standard 200-ns pulses. Tunable CO2 lasers in combination with this technique should yield a source in the 0.1–3.0-THz range.