Photo-Dember Terahertz Emitter Excited With An Er:Fiber Laser

A terahertz emitter based on the lateral photo-Dember effect is shown to efficiently generate terahertz radiation with a peak frequency of 0.7 THz and an electric field amplitude up to 5 V/cm when excited by 90 fs pulses centered at 1.55 mu m. A thin layer of In(0.53)Ga(0.47)As grown on InP provides the substrate material in which unidirectional lateral photo-Dember currents are excited. Since photo-Dember terahertz emitters do not require an external bias, they do not suffer from high dark currents limiting the application of biased InGaAs photoconductive terahertz emitters. (C) 2011 American Institute of Physics. [doi:10.1063/1.3543627]