A new Li2O-SrO-Nb2O5-P2O5 glass system was prepared by a high-temperature alumina crucible, and structural characterisation and optical properties were investigated. Proper content of Li2O and Nb2O5 was employed to replace partial SrO and P2O5 to improve the optical properties. It was observed that the enhancement of the RI from 1.75 to 1.85 is mainly due to the Nb2O5 content. An addition of Li2O significantly increases the optical transmittance; optical transparency can be enhanced from 60% to higher than 85% in the UV-visible region with addition of 20-40 mol% Li2O species. However, optical transmittance is monotonically decreased from about 90% to 80% under 10-30 mol% Nb2O5 addition. The 40P2O5-20Nb2)5-20SrO-20Li2O glasses demonstrate the optimum RI (n>1.75) and high optical transparency (>80%) in the UV-visible region.
