Generation of multicycle terahertz pulses via optical rectification in periodically inverted GaAs structures

The authors demonstrate the generation of multicycle narrow-bandwidth terahertz pulses in periodically inverted GaAs structures using optical rectification of 2 um, 100 fs pump pulses. Three different types of orientation-inverted samples are employed: optically contacted multilayer, orientation-patterned, and diffusion-bonded GaAs. The terahertz pulses are characterized by two-color (pump at 2 um and probe at 0.8 um) terahertz time-domain spectroscopy and terahertz Michelson interferometry.