Dysprosium doped alkali fluoroborate glasses—Thermal, structural and optical investigations

Thermal, structural and optical properties of Dy³⁺-doped alkali fluoroborate glasses with composition (in mol%), 49B₂O₃+25XO+25NaF+1Dy₂O₃ (where X=Li₂, Na₂, K₂, Mg and Ca), have been investigated. Thermal analysis revealed the homogeneous formation of the glasses. The FTIR spectra reveal that the glasses contain BO₃, BO₄ non-bridging oxygen atoms and strong OH⁻ bonds. From the optical absorption spectra, Judd-Ofelt intensity parameters (Ω_λ, λ=2, 4 and 6) have been evaluated and are in turn used to predict radiative properties such as radiative transition probability (A), stimulated emission cross-section () and branching ratios (β_R) for the excited levels of Dy³⁺ ions in alkali fluoroborate glasses. The dependence of the spectral characteristics of Dy³⁺ ions due to compositional changes has been examined and reported.     

Structural, optical and thermal investigations on Dy doped NaF–Li2O–B2O3 glasses

Structural, optical and thermal properties of Dy³⁺ doped lithium fluoroborate glasses have been studied for various concentrations of Dy³⁺ from 0.5 to 5 wt%. The XRD studies confirm the amorphous nature of the glasses while the FTIR spectra reveal the presence of BO₃ and BO₄ local structural units. The UV–VIS–NIR absorption studies were carried out to calculate the bonding parameters ( and δ), to identify the ionic/covalent nature of the glasses. The JO parameters, experimental and theoretical oscillator strengths were also determined and reported. The luminescence spectra have been studied to determine the radiative transition probability (A), stimulated emission cross section () and the experimental and calculated branching ratios (β_R) for the excited levels that include ⁴F_9/2→⁶H_11/2, ⁶H_13/2, and ⁶H_15/2 transitions. The variation of optical properties with varying concentrations of dysprosium oxide content in the glasses are reported and discussed. The thermal behavior of Dy³⁺ doped lithium fluoroborate glasses have been reported by recording DSC thermograms.     

Composition dependent structural and optical properties of Sm-doped sodium borate and sodium fluoroborate glasses

Sodium borate and fluoroborate glasses doped with trivalent samarium (Sm³⁺) were prepared and their detailed spectroscopic analysis was carried out. The FTIR spectra reveal that, the glasses contain BO₃, BO₄, non-bridging oxygen and strong OH⁻ bonds. From the optical absorption spectra, Judd-Ofelt intensity parameters (Ω_λ, λ=2, 4 and 6) have been evaluated and are in turn used to predict radiative properties such as radiative transition probability (A), stimulated emission cross section () and branching ratios (β_R) for the excited levels of Sm³⁺ ions in sodium borate and sodium fluoroborate glasses. The dependence of the spectral characteristics of Sm³⁺ ions due to compositional changes have been examined and reported. The value is found to decrease with the decrease in the sodium content in the glass. The decay from the ⁴G_5/2 level is found to be non-exponential indicating a cross-relaxation among the Sm³⁺ ions.     

Spectroscopic investigations and luminescence spectra of Nd and Dy doped different phosphate glasses

Spectral properties of Nd³⁺ and Dy³⁺ ions in different phosphate glasses were studied and several spectroscopic parameters were reported. Covalency of rare-earth-oxygen bond was studied in these phosphate glass matrices with the variation of modifier in host glass matrix. Using Judd-Ofelt intensity parameters (Ω₂, Ω₄ and Ω₆), radiative transition probabilities (A) and radiative lifetimes (τ_R) of certain excited states of Nd³⁺ and Dy³⁺ ions are estimated in these glass matrices. From the magnitudes of branching ratios (β_R) and integrated absorption cross-sections (Σ), certain transitions of both the ions are identified for laser excitation. From the emission spectra, peak stimulated emission cross-sections (σ_P) are evaluated for the emission transitions observed in all these phosphate glass matrices for both Nd³⁺ and Dy³⁺ ions.     

Spectroscopic and optical properties of Nd doped fluorine containing alkali and alkaline earth zinc-aluminophosphate optical glasses

Nd³⁺ doped fluorine containing zinc-aluminophosphate glasses have been prepared with alkali and alkaline earth content to understand the effect of network modifiers on radiative process. The physical and optical properties of these glasses have been evaluated. The Judd-Ofelt model for the intensity analysis of induced electric dipole transitions has been applied to the measured oscillator strengths of the absorption bands to determine the three phenomenological intensity parameters Ω₂, Ω₄ and Ω₆ for each glass. Using these parameters, transition probability (A), total transition probability (A_T), branching ratios (β_R) radiative life times (τ_R) and integrated cross-section (σ_a) for the stimulated emission have been theoretically calculated for certain excited Nd³⁺ fluorescent levels. From the obtained results the conclusion is made about the possibility of using these glasses as laser material.