Subterahertz self-oscillations of depletion of electron populations in the conduction band of GaAs in the presence of pumping and intrinsic stimulated radiation

It was previously found that, during picosecond optical pumping, ultrafast interrelated self-modulations of fundamental absorption of light and intrinsic stimulated picosecond radiation emerge in GaAs. In this study, quantitative evaluations confirming the assumption that the mentioned self-modulations are caused by self-oscillations of depletion of electron populations in the conduction band are made. The relation for the frequency of self-oscillations of depletion of populations is obtained. The presence of conditions for self-organization leading to the emergence of periodic nonlinear waves in nonequilibrium media, which is photogenerated electron-hole plasma with depletions of populations, is shown. As a result, in a series of studies, including this one, it is found that the collective excitation of charge carriers—self-oscillations of depletion of populations of the conduction band—emerges during pumping in GaAs under the effect of intrinsic stimulated radiation.