Erbium luminescence properties of niobium-rich oxide glasses

Erbium luminescence has been investigated in niobium borophosphate glass. A correlation between luminescence intensity at 1532 nm, OH absorption and the structure of the glass network was established as a function of the niobium oxide concentration. An increase of the radiative efficiency corresponding to 4I13/2 → 4I15/2 (4f–4f) transition of Er3+ ions has been observed for niobium richest glasses. The modification of the Er3+ ions site is analyzed as a function of the niobium concentration. A Judd–Ofelt analysis has been applied to emphasize the structural change. An increase of the up conversion was also measured as the niobium oxide content increases.