Studies of the temporal and spectral shape of terahertz pulses generated from photoconducting switches

Abstract

We present a systematic investigation of the operation conditions of photoconductive switches fabricated on LT-GaAs as sources of THz pulses. We find a pronounced dependence of the THz pulse intensities and spectra on bias voltage and excitation density, which can be explained in terms of carrier dynamics and screening of the electric bias field. This study provides guidelines for the selection of the optimal operation parameters to obtain short THz pulses with a given geometry of the photoconductive switch.