Optically excited THz generation from ordered arrays of GaAs nanowires

THz generation under excitation by ultrashort optical pulses from ordered arrays of GaAs nanowires is reported. It was found that the efficiency of THz generation is determined by the geometrical parameters of nanostructures and has a resonant character. Furthermore, it is shown that the terahertz generation efficiency at optimum geometrical parameters of an array of semiconductor nanowires is greater than the corresponding value for bulk semiconductor p-InAs which is the most effective THz emitter.