A theory of two-wave saturation spectroscopy with subpicosecond relaxation time in p-Ge

Time evolution of the nonequilibrium hole distribution function is followed by numerical integration of Boltzmann's equations in p-Ge taking into account anisotropic band structure. Both the hole-burning and light-light modulation experiments of Keilmann can be reasonably explained by a simple model. Subpicosecond relaxation time for these processes is obtained in good agreement with Keilmann's estimate.