Picosecond Optically Induced Anisotropic State Filling in Semiconductors

Abstract

Picosecond self-diffraction is observed from transient orientational gratings produced in germanium by an anisotropic (in $k$ space) filling of the optically coupled states by direct absorption of the nearly monochromatic polarized exciting radiation, the first direct observation of anisotropic state filling in semiconductors. A new theoretical model is presented briefly; agreement is found with all aspects of the experiment.