Electrical and Radiation Characteristics of Semilarge Photoconductive Terahertz Emitters

Abstract

We present experimental characterization of semilarge photoconductive emitters, including their electrical/photoconductive parameters and terahertz spectra. A range of emitters were studied and fabricated on both LT-GaAs and SI-GaAs, having a variety of electrode geometries. The spatial cone of terahertz radiation was defined. The dependencies of the photocurrent and the terahertz power on the bias voltage and the laser power were determined. A Fourier-transform interferometer is used to determine the terahertz spectra and to clarify the effects of the substrate and electrode geometry.