Light-controlled semiconductor waveguide antenna

A rectangular dielectric waveguide of intrinsic semiconductor material has been investigated for an application in the 30¿40 GHz range. The resistivity of the semiconductor material has locally been changed by GaAs-laser-beam illumination. Depending on the pattern and intensity of the light spot, the generated waveguide inhomogeneity behaves essentially as a termination, a short circuit or an antenna element. This effect can be controlled in position and time. Hence the optically controlled waveguide can be used either as an antenna for fast aperture scanning or as a simple optoelectronically tuned antenna array.