Concentration dependences of the quantum efficiency of the luminescence emitted by neodymium-activated laser matrices and microscopic determination of these dependences

A description is given of the spectroscopic properties of the Nd³⁺ ion in various solid-state laser matrices. The effects which may result in multipole interaction between Nd³⁺ ions are considered. An analysis is made of the origin of the difficulties encountered in the determination of the quantum efficiency of the luminescence from the ⁴F_3/2 level of Nd³⁺ in various matrices. It is shown that the current ideas on the relationships governing the dissipation of the excitation energy of the Nd³⁺ ions and the existing measurement methods make it possible to determine the concentration dependences of the quantum efficiency of the luminescence from the ⁴F_3/2 level of Nd³⁺ in various matrices. The published data and the authors' own results, reported below, are used in plotting the concentration dependences of the quantum efficiency of the luminescence from the ⁴F_3/2 level of Nd³⁺ in a variety of solid-state laser matrices. A method for calculating such dependences for crystals is proposed.