Wide-band continuous-wave terahertz source with a vertically integrated photomixer

A transverse electromagnetic horn antenna is monolithically integrated with a low temperature grown GaAs vertical photodetector on a silicon substrate forming a vertically integrated photomixer. Continuous-wave terahertz radiation is generated at frequencies up to 3.5 THz with a power level reaching 20 nW around 3 THz. Microwave and material concepts allow both qualitative and quantitative explanations of the experimental results. The thin film microstrip line topology has been adapted for active devices by an Au–Au thermocompression layer transfer technique and seems to be a promising generic tool for a new generation of efficient terahertz devices.