Absorption saturation and self-action processes under resonant excitation of the basic exciton transition in CdSe/ZnS colloidal quantum dots

Abstract: The revealed absorption saturation and Fresnel diffraction of ultrashort laser pulses under resonant excitation of the basic exciton transition in CdSe/ZnS quantum dots (a strongly absorbing colloidal solution) have been explained by the processes of filling of states of a two-level system with the excited-state lifetime dependent on the light intensity and self-diffraction of the laser beam due to the formation of the transparency channel and the induced diaphragm.