Pump polarization dependence of optical rectification for 112A GaAs

A general theory for the pump polarization angle dependence of optical rectification has been constructed. Measurements have been taken of a 112A GaAs sample and compared to this theory. The terahertz radiation generated is a mixture of bulk (second order) and surface (third order) contributions. From this data, and a previous investigation into the azimuthal angle dependence of these samples, a value of the β term in the third order non-linear polarization can be obtained.