Effects of Nb 2 O 5 on thermal stability and optical properties of Er 3+ -doped tellurite glasses

Abstract

Er3+-doped tellurite glasses with molar compositions of xNb2O5−(14.7−x)Na2O–10ZnO–5K2O–10GeO2– 60TeO2–0.3Er2O3 (x = 0,3,5,7 and 9) have been investigated for developing 1.5 μm fibre and planar amplifiers. The effects of Nb2O5 on the thermal stability and optical properties of Er3+-doped tellurite glasses have been discussed. It is noted that the incorporation of Nb2O5 (x = 5) increases the thermal stability of tellurite glasses significantly. Er3+-doped niobium tellurite glasses exhibit a large stimulated emission cross-section (7.2×10−21−10.7×10−21 cm2) and the gain bandwidth, FWHM×σepeak (274×10−28−480×10−28 cm3), which are significantly higher than that of silicate and phosphate glasses. In addition, the intensity of upconversion luminescence of the Er3+-doped niobium tellurite glasses decreases rapidly with increasing Nb2O5 content. As a result, Er3+-doped niobium tellurite glasses might be a potential candidate for developing laser or optical amplifier devices.