A new THz-photomixer based on a n-i-p-n doping superlattice

We investigate a THz-photomixer based on quasi-ballistic transport in an asymmetric n-i-p-n superlattice. The measured frequency roll-off is due to the device RC time constant alone whilst the transit-time limitation is overcome in this device. Measured power levels compare well with those from standard LT-GaAs photomixers.