Highly efficient terahertz detection by optical mixing in a Fabry-Perot cavity LT-GaAs photoconductor

It is shown from accurate on-wafer measurement that a low-temperature-grown GaAs photoconductor using a metallic mirror Fabry-Perot cavity can serve as highly efficient optoelectronic heterodyne mixer in the terahertz frequency range. Conversion losses of 22 dB at 100 GHz and ~27 dB at 300 GHz were measured, which is an improvement by a factor of about 40 dB as compared with the previous values obtained with photoconductors.