Spectroscopic properties of Yb2+ in aluminosilicate glass

摘要

In contrast to Yb3+ which is a well-investigated optically active ion, the spectroscopic properties of its divalent counterpart Yb2+ in glasses are hardly investigated, although Yb2+ might have a notable influence on the luminescence properties of Yb3+-doped glasses even at low Yb2+ concentrations because of its strong f-d transitions. In this paper, we report on the preparation and spectroscopic properties of Yb2+-doped aluminosilicate glasses that were produced using the normal melt-quench technique. The glass composition is 20CaO20Al(2)O(3)60SiO(2) (mol). To achieve a sufficient amount of Yb2+ in the samples, different methods were applied to influence the red-ox equilibrium during glass melting: firstly, under argon atmosphere and additional argon bubbling, and secondly by the addition of metallic aluminum powder to the batch. The strongly reduced samples show a greenish to brownish yellow coloring which could be attributed to the strong absorption of Yb2+ ions in the UV to blue spectral range. The absolute Yb2+ concentration in the glass and the molar extinction coefficient of Yb2+ was obtained by spectroscopic measurements. If irradiated with UV light, the Yb2+-doped samples show a broad fluorescence emission in the wavelength range from 450 to 700nm with a peak at around 515nm.