Femtosecond coherent transient processes in semiconductors and heterostructures and the possibility of creation of semiconductor laser refrigerator

The article provides the results of the experiments on femtosecond four-wave mixing in CdS crystal and in two-dimensional electron gas layer at the GaAs/AlGaAs interface at room temperature. The phase relaxation time and the values of diffusion coefficient for spins and electrons are determined. Some peculiarities of the coherent response decay curves make it possible to assume that the optical dephasing is due to exciton-exciton interaction. The concept of laser cooling for semiconductors and heterostructures is discussed.