Interferometric characterization of 160 fs far-infrared light pulses

Abstract
We report the first interferometric characterization of freely propagating, subpicosecond, far-infrared (FIR) light pulses. FIR light was generated via short pulse photoexcitation of a semi-insulating InP wafer. The half width of the intensity interferogram was 230 fs. The FIR light contained frequency components from 3 to 150 cm−1.