Judd–Ofelt analysis of Er+3 activated lead free fluoro–tellurite glass

A series of lead free fluoro–tellurite glasses containing different concentration of Er2O3 were prepared and the optical properties of the best luminescent sample (1 g mol% of Er2O3) have been investigated by Judd–Ofelt theory to judge its suitability as practical photonic material. Three intensity parameters Ω2 = 4.935 × 10−20 cm2, Ω4 = 3.148 × 10−20 cm2, Ω6 = 1.745 × 10−20 cm2 of the ion in the glass, were determined from the optical absorption data, which were used to calculate the parameters like the radiative transition probabilities (Ar), radiative life-times (τf), fluorescence branching ratios (βc) and the integrated emission cross-section (Σσ) of its different transitions. Experimental optical absorption intensity and the calculated values of oscillator strength (P), suggested that the Er+3 ions in the glass can most effectively be excited by 4I15/2 → 4G11/2 (376 nm), 4I15/2 → 4F7/2 (486 nm) and 4I15/2 → 2H11/2 (519 nm) transitions while calculated spontaneous emission rate (Ar) values showed that strong visible emissions at 650 nm and 546 nm should occur, respectively, through (4F9/2 → 4I15/2) and (4S3/2 → 4I15/2) transitions and NIR emissions at 1532, 1222, 974 and 838 nm, respectively, through (4I13/2 → 4I15/2), (4S3/2 → 4I11/2), (4I11/2 → 4I15/2), and (4S3/2 → 4I13/2) transitions. The spectroscopic data indicate that the present glass is a prospective photonic material for practical applications in the visible and NIR region.