Characterization of optical transitions for some new laser materials

The paper is devoted to investigate some doped oxide crystals: diphosphate M^IMe^IIIP₂O₇ (M = Na, K. Cs; Me = Al, In) crystals doped with Cr³⁺ ions, potassium titanyl orthophosphate KTiOPO₄ crystals doped with Cr³⁺, Nd³⁺ and Eu³⁺ ions, silicate akermanite Me₂SiO₄ (Me = Ca, Mg) crystals doped with Cr³⁺ ions. Possibility of the impurity ions to form at the same crystal lattice various charge states must be taken into account at a design of the complex oxide materials on the contrary to the other simple oxides, f.e. Al₂O₃ crystals, where the chromium ions are arranged mainly in the Cr³⁺ charge state. Luminescence spectra of the noted crystals were investigated. The energy schemes of the electron states of the impurity ions in the various crystal matrices are considered taking into account the Tanabe-Sugano diagram and the known schemes of electron levels of rare earth ions. Values of Dq and ΔE_TE were calculated for various crystal lattices doped with Cr³⁺ ions. Some spectroscopy parameters were estimated for the most intensive transitions in spectra of the studied materials.