Vol. 33, Issue 1, pp. 175-181 (2003)

Abstract

The UV and visible optical spectra (absorption, emission and luminescence excitation) of the          Ho-doped CaO–Ga₂O_3–GeO₂ glasses at room and liquid nitrogen temperatures have been investigated for the first time. The Ho-doped (C_Ho = 0.7 wt%) glass samples with garnet Ca₃Ga₂Ge₃O₁₂ (or 3CaO–Ga₂O_3–3GeO₂) composition were prepared by the conventional high -temperature synthesis technique. By optical and EPR spectroscopy it has been shown that the holmium impurity is incorporated into the glass network as Ho³⁺ (4f¹⁰, ⁵I₈) ions, exclusively. All transitions of the Ho³⁺ ions observed in optical spectra of Ho-doped 3CaO–Ga₂O_3–3GeO₂ glasses are identified. The Ho³⁺ optical absorption spectrum has been analyzed and described in the framework of Judd–Ofelt theory. Optical absorption and emission spectra of the Ho³⁺ ions in the 3CaO–Ga₂O_3–3GeO₂ glasses are quite similar to Ho³⁺ optical spectra in other oxide glasses and are characterized by statistical distribution of the local crystal field parameters. Incorporation peculiarities and spectroscopic properties of Ho³⁺ impurity ions in the glasses of CaO–Ga₂O_3– GeO₂ system are discussed.