Novel and optically efficient multicomponent tellurite glasses doped with Eu 3þ ions were prepare... more Novel and optically efficient multicomponent tellurite glasses doped with Eu 3þ ions were prepared by melt quenching procedure. Absorption, photoluminescence excitation, emission and Raman spectra analyses of the Eu 3þ-doped glasses have been carried out. Spectroscopic studies were performed with the Judd-Ofelt and phonon side band analyses. The local vibrational mode around Eu 3þ ions and the phonon energy of the prepared tellurite glasses was estimated by the phonon side band (PSB) associated with 7 F 0 / 5 D 2 transition of Eu 3þ ion. Both the phonon energy (ћu) and the electron-phonon coupling constant (g) were derived from the phonon side band spectrum. Radiative properties such as spontaneous transition probabilities (A T), radiative lifetime (t R) and luminescence branching ratio (b R) ratio were calculated for different excited states. Five pronounced peaks have appeared in the photo-luminescence spectra (PL) as a result of the transitions from the metastable 5 D 0 to the ground states 7 F J (J ¼ 0 to 4) of Eu 3þ ions. The red Eu 3þ emission at 612 nm corresponding to the 5 D 0 / 7 F 2 transition is of particular importance and its emission intensity is observed to increase significantly with growing Eu 3þ ion concentration, suggesting that these multicomponent tellurite glasses are suitable candidates for red laser source applications.
In the present work, multicomponent tellurite glasses were elaborated by the melt quench techniqu... more In the present work, multicomponent tellurite glasses were elaborated by the melt quench technique with different concentrations of Er 3 þ ions. Amorphous nature of all the glasses was confirmed using X-ray diffraction patterns. The thermal parameters, such as glass transition temperature (T g) and the onset of crystallization temperature (T X), were determined by the differential scanning calorimetry. Judd–Ofelt parameters were derived for 0.5 mol% Er 3 þ-doped glass from the absorption measurements, and in turn, used to find the radiative properties of 4 S 3/2 , 2 H 11/2 and 4 I 11/2 levels of Er 3 þ ion. A green emission corresponding to 4 S 3/2-4 I 15/2 and 2 H 11/2-4 I 15/2 transitions of Er 3 þ ions was observed in the glasses under investigation. Efficient green upconversion luminescence was observed under 976 nm excitation. The emission bands centered at 529 and 543 nm confirmed that two photons contribute to the upconversion processes. We have also analyzed the dependence of downconversion as well as upconversion as a function of Er 3 þ ion concentration, which shows quenching of photoluminescence intensity above 0.5 mol% doping. From the emission spectra, CIE color coordinates of 0.5 mol% Er 3 þ-doped glass was examined. Fluorescence decay curves for the 4 S 3/2-4 I 15/2 transition for all the doped glasses have been measured and analyzed. Absorption cross-section and calculated emission cross-section, using the McCumber method, for the 4 I 13/2 2 4 I 15/2 transitions were evaluated and discussed.
Novel and optically efficient multicomponent tellurite glasses doped with Eu 3þ ions were prepare... more Novel and optically efficient multicomponent tellurite glasses doped with Eu 3þ ions were prepared by melt quenching procedure. Absorption, photoluminescence excitation, emission and Raman spectra analyses of the Eu 3þ-doped glasses have been carried out. Spectroscopic studies were performed with the Judd-Ofelt and phonon side band analyses. The local vibrational mode around Eu 3þ ions and the phonon energy of the prepared tellurite glasses was estimated by the phonon side band (PSB) associated with 7 F 0 / 5 D 2 transition of Eu 3þ ion. Both the phonon energy (ћu) and the electron-phonon coupling constant (g) were derived from the phonon side band spectrum. Radiative properties such as spontaneous transition probabilities (A T), radiative lifetime (t R) and luminescence branching ratio (b R) ratio were calculated for different excited states. Five pronounced peaks have appeared in the photo-luminescence spectra (PL) as a result of the transitions from the metastable 5 D 0 to the ground states 7 F J (J ¼ 0 to 4) of Eu 3þ ions. The red Eu 3þ emission at 612 nm corresponding to the 5 D 0 / 7 F 2 transition is of particular importance and its emission intensity is observed to increase significantly with growing Eu 3þ ion concentration, suggesting that these multicomponent tellurite glasses are suitable candidates for red laser source applications.
In the present work, multicomponent tellurite glasses were elaborated by the melt quench techniqu... more In the present work, multicomponent tellurite glasses were elaborated by the melt quench technique with different concentrations of Er 3 þ ions. Amorphous nature of all the glasses was confirmed using X-ray diffraction patterns. The thermal parameters, such as glass transition temperature (T g) and the onset of crystallization temperature (T X), were determined by the differential scanning calorimetry. Judd–Ofelt parameters were derived for 0.5 mol% Er 3 þ-doped glass from the absorption measurements, and in turn, used to find the radiative properties of 4 S 3/2 , 2 H 11/2 and 4 I 11/2 levels of Er 3 þ ion. A green emission corresponding to 4 S 3/2-4 I 15/2 and 2 H 11/2-4 I 15/2 transitions of Er 3 þ ions was observed in the glasses under investigation. Efficient green upconversion luminescence was observed under 976 nm excitation. The emission bands centered at 529 and 543 nm confirmed that two photons contribute to the upconversion processes. We have also analyzed the dependence of downconversion as well as upconversion as a function of Er 3 þ ion concentration, which shows quenching of photoluminescence intensity above 0.5 mol% doping. From the emission spectra, CIE color coordinates of 0.5 mol% Er 3 þ-doped glass was examined. Fluorescence decay curves for the 4 S 3/2-4 I 15/2 transition for all the doped glasses have been measured and analyzed. Absorption cross-section and calculated emission cross-section, using the McCumber method, for the 4 I 13/2 2 4 I 15/2 transitions were evaluated and discussed.
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