Absorption and Emission Spectral Properties of Pr ³⁺ , Nd ³⁺ , and Eu ³⁺ Ions in Heavy‐Metal Oxide Glasses

The optical properties of the heavy‐metal oxide glasses 70PbO . 30TiO 2 ,70PbO . 30CdO, and 70PbO . 30TeO 2 doped with Pr 3+ ,Nd 3+ ,and Eu 3+ ions have been investigated. The transition energies of the absorption spectra of Pr 3+ and Nd 3+ ions are analyzed for the Racah parameters, configuration interaction terms, and spin‐orbit coupling. The absorption spectral intensities of Pr 3+ and Nd 3+ ions are analyzed for the Judd–Ofelt parameters. The Judd–Ofelt parameter, Ω 2 ,suggests strong covalency for the Ln–O bond in these oxide glass matrices for both Pr 3+ and Nd 3+ ions and follow the order 70PbO . 30TiO 2 > 70PbO . 30CdO > 70PbO . 30TeO 2 .This trend has been correlated to that of oxide ion polarizabilities, which follow the same order. The radiative parameters, viz. , transition probability ( A ), branching ratios (β R ), and stimulated emission cross sections (σ p ), for laser transitions have been obtained. The high Ω 2 for Pr 3+ leads to significantly larger σ p for the 3 P 0 → 3 F 2 transition in these glass matrices compared to those in fluoride and oxyfluoride glasses. The room‐temperature emission 1 D 2 → 3 H 4 transition of Pr 3+ is much larger in 70PbO . 30TiO 2 than in the other two glass systems. The emission spectra of Pr 3+ show temperature effects due to the Boltzmann population. The red‐to‐orange intensity ratios in the emission spectra of Eu 3+ also support strong covalency of the Ln–O bond. The phonon side‐band spectra (PSB) of Eu 3+ are correlated with the infrared spectra. The electron–phonon coupling strengths and phonon energies have been obtained in all the cases.