| Autor: |
M MJ Jayasimhadri, L LRM Moorthy, K KK Kojima, K KY Yamamoto, Noriko NW Wada, Noriyuki NW Wada |
| Zdroj: |
Journal of Physics D: Applied Physics; 2/21/2006, Vol. 39 Issue 4, p635-641, 7p |
| Abstrakt: |
Optical absorption and emission spectra were performed for Dy3+ ions doped alkali tellurofluorophosphate glasses. The intensity parameters from the measured oscillator strengths were evaluated using the Judd–Ofelt (J–O) theory. The observed and calculated oscillator strengths (f) are found to be in reasonable agreement with one another. The evaluated J–O parameters are used to predict radiative transition probabilities (AR), total radiative transition probabilities (AT), radiative lifetimes (τR) and branching ratios (βR) for various excited levels of Dy3+ doped alkali tellurofluorophosphate glasses. The predicted τR and βR values of 4F9/2 transition are compared with the experimentally measured values. The lifetime of the 4F9/2 level was measured with a quantum efficiency of 80% for Dy3+: RTFP (R = Li, Na, K) glasses. Stimulated peak emission cross-sections (σe) for different emission transitions were estimated from emission spectra. From the magnitudes of the stimulated emission cross-sections, branching ratios, multiphonon relaxation rates (WMP), the most potential laser transitions are identified and the utility of these glasses as laser active materials is discussed. A thermalization process between the 4F9/2 and 4I15/2 levels is also reported. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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