Oxyfluoride germanatetellurite glasses doped with dysprosium-Spectroscopic characteristic and luminescence thermometry qualities

Germanatetellurite glasses doped with different concentrations of dysprosium were manufactured and studied utilizing various optical spectroscopy techniques. Radiative transition rates, branching ratio of luminescence and radiative F-4(9/2) lifetime were estimated for material under study. The impact of the glass host and the incorporation of luminescent ions on the temperature-dependent absorption and luminescence characteristics were investigated in a temperature range of 300-675K. Detailed analysis of the absorption spectra showed that efficiency of the UV Dy3+ excitation can be significantly reduced especially at higher temperatures. Fluorescence intensity ratio (FIR) between thermally-coupled I-4(15/2)/F-4(9/2) multiplets gradually increased with temperature rinsing and eventually, absolute and relative sensitivities were estimated. The effective Dy-Dy interactions take place in the studied germanatetellurite glasses and critical radius R-0 was found to be 5.8 angstrom. It was revealed that near infrared femtosecond pulses can be converted on blue and yellow dysprosium luminescence as result of up-conversion phenomena in the examined oxyfluoride glass.