Angular distribution of terahertz radiation emitted from semiconductor surfaces

摘要

Photo-current transients at semiconductor surfaces can give rise to terahertz (THz) frequency pulse generation, with the angular distribution of the THz emission allowing identification of the photo-current direction. We show that in-plane photo-currents can lead to much stronger THz pulses than photo-currents normal to the surface, with the resultant amplitude and directivity of the emitted radiation being controlled by the shape of the excitation beam.