Исследование мощности люминесценции экситонов и примесно-дефектных центров, возбуждаемых с помощью двухфотонного поглощения

In the present work, using as an example ZnSe: Fe2+ single crystals, it was experimentally and theoretically studied the effect of the average power of femtosecond laser radiation on the average luminescence power of excitons and impurity-defect centers upon two-photon excitation of the electronic system of a crystal. It has been experimentally shown that the average luminescence power of crystal excitons in the studied range of excitation powers is proportional to 4 degrees of the average excitation radiation power. The average luminescence power of impurity-defect centers has a quadratic character. A theory is constructed that explains the experimentally observed dependencies. It is noted that the nature of the dependence of the crystal luminescence on the pump power during two-photon excitation can be used to estimate the degree of contamination of the crystal by impurity-defect centers.