64 μW pulsed terahertz emission from growth optimized InGaAs/InAlAs heterostructures with separated photoconductive and trapping regions

We present results on optimized growth temperatures and layer structure design of high mobility photoconductive Terahertz (THz) emitters based on molecular beam epitaxy grown In_0.53Ga_0.47As/In_0.52Al_0.48As multilayer heterostructures (MLHS). The photoconductive antennas made of these MLHS are evaluated as THz emitters in a THz time domain spectrometer and with a Golay cell. We measured a THz bandwidth in excess of 4 THz and average THz powers of up to 64 μW corresponding to an optical power-to-THz power conversion efficiency of up to 2 × 10⁻³.