Enhanced electronic transition probabilities and line intensities of Er+ 3 ion in a (W, La)-tellurite glass as revealed from Judd–Ofelt analysis

A series of tellurite glasses containing dispersed Er2WO6 nanocrystals of different concentration was prepared, and the optical properties of the best luminescent sample (1 g mol% of Er2O3) were investigated by Judd–Ofelt theory. The intensity parameters Ω2(=8.410×10−20cm2), Ω4(=4.833×10−20 cm2)Ω4(=4.833×10−20 cm2), Ω6(=2.027×10−20 cm2)Ω6(=2.027×10−20 cm2) of the Er+3 ion in the glass were determined and then used to calculate parameters such as the radiative transition probabilities (ArAr), radiative life-times (τfτf), fluorescence branching ratios (βcβc) and the integrated emission cross-section (ΣσΣσ) of different transitions. The experimental optical constant and the calculated oscillator strength values (PP) suggest that the Er+3 ions in the glass can most effectively be excited by 4I15/2→4F7/2 (489 nm) and 4I15/2→2H11/2 (522 nm), 4I15/2→4F9/2 (653 nm) and 4I15/2→4I13/2 (1533 nm) transitions while the spontaneous emission rate (ArAr) values show that strong visible emissions should occur respectively through (4F9/2→4I15/2) and (4S3/2→4I15/2) transitions and strong NIR emissions through (4I13/2→4I15/2), (4S3/2→4I11/2), (4F9/2→4I13/2), (4I11/2→4I15/2), (4S3/2→4I13/2) transitions. The spectroscopic parameters show that the glass is a superior photonic material compared to other known Er+3 doped glass and crystals.