Abstract:
Our group purchased a THz photomixer from the Millimeter Wave Technology
Group at the Rutherford Appleton Laboratory in London, UK. A photomixer is based on
optical heterodyne conversion where a photoconductor or photodiode is illuminated by two
laser beams with a difference frequency in the THz region. The beat frequency of the
two lasers will modulate the conductivity of the photomixer material. The variation of
the conductivity is converted to electrical current and finally radiation by applying a bias
voltage across the active region of the device. My thesis concerns the determination of the
characteristics of the photomixer, which is an expensive and extremely sensitive piece of
equipment, to optimize its performance in support of a number of research activities within
the group.