ABSTRACT
The discovery of quantum generators and fast development of quantum electronics have stimulated theoretical development and investigation of the interaction of electrons with matter as well as the electromagnetic field. The probability of the multiphoton absorption is computed by summing the perturbation series considering the interaction of charge carriers with light field. The new aspect of the multiphoton absorption problem involves the interaction of the strong electromagnetic radiation with nanocrystals and with longitudinal optical phonons. The dimensional quantization of the electronic energy spectrum in mesoscopic structures presents new particularities in the absorption process compared to ones in unbounded media. The absorption spectrum has the form of stripes whose intensity depends on the resonance character. The most pronounced absorption is at the triple resonance, where values of radiation and oscillatory and optical phonon frequencies are equal.
