Open semiconductor waveguide for millimeter wave application

A rectangular dielectric semiconductor waveguide is theoretically investigated by transverse mode matching methods. In an experiment the resistivity of the semiconductor material is changed by illuminating with a GaAs laser beam. Depending on the configuration and intensity of the light spot the waveguide behaves like a termination or a short. This effect is controllable in position and time. In a further step the radiation from a local inhomogeneity in an open structure is intentionally used for generating a light-controlled radiating element.