Effect of La2O3 upon optical properties of oxy-fluoride glasses

In this paper, the bonding states between composition ions and changes in the optical properties of glass according to the amount of substitution of La2O3 in La2O3-CaF2-Al2O3-SiO2 glass (hereinafter referred to as LCAS glass system) were studied. By analyzing the molar volume, density, and number of chemical bonds per unit volume of LCAS glass, it was confirmed that the added La2O3 acted as a glass network modifier. As the amount of substitution of La2O3 increased, the numbers of non-bridging oxygen and electron polarization increased, thereby reducing the optical band gap of the glass. As a result, it was confirmed that semiconducting behavior was exhibited in the glass. The La2O3-CaF2-Al2O3-SiO2 glass prepared in this study had a light transmittance of 75% or more, and the optical band gap energy could be changed as a function of amount of La2O3 substitution. It is concluded that LCAS glass can be used in various optical device fields such as optical sensors and lasers by controlling the amount of La2O3 substitution.