Abstract:
Anisotropic photoconductivity at a difference frequency, excited in a semiconductor by linearly polarized two-frequency optical radiation, is considered. The anisotropy of the photoconductivity arises due to the optical alignment of photoexcited electrons momenta and dependence of their effective mass and momentum relaxation time on energy. It is shown that the contribution of the anisotropic photoconductivity to the photocurrent at the difference frequency lying in the terahertz frequency range can be comparable with that of the isotropic photoconductivity. This effect can manifest itself in photoconductive antennae, devices used to generate terahertz radiation.