Impact of the O/P ratio on the optical properties and structures of fluoride-phosphate glass

Ca(PO3)(2)-AlF3-CaF2-BaF2-BaO glasses were prepared by the melt quenching method, and the effects of the O/P ratio on the optical properties and glass structure were investigated. The bandgap energy showed no significant change at O/P = 3.0-3.4 but drastically decreased with the increase in the O/P from 3.6 to 4.0. In addition, the refractive index dispersion was analyzed based on the Lorentz model, and it was found that the decrease in the resonance frequency in the ultraviolet region with the increase in the O/P ratio resulted in an increase in the refractive index and dispersion. Analysis of the infrared absorption and Raman scattering spectra revealed that the phosphate chains were broken, and isolated Q(0) units were generated with the increase in the O/P ratio from 3.6 to 4.0. Based on the structural change of the glass, the origin of the nonlinear dependence of the optical properties on the O/P ratio was discussed.

Automated summary

Ca(PO3)(2)-AlF3-CaF2-BaF2-BaO glasses were prepared using the melt quenching method, and the effects of the O/P ratio on the optical properties and glass structure were investigated. The bandgap energy remained stable at O/P = 3.0-3.4 but decreased significantly with an increase in the O/P ratio from 3.6 to 4.0. The refractive index dispersion increased due to a decrease in the resonance frequency in the ultraviolet region as the O/P ratio increased. Changes in the glass structure, such as the breaking of phosphate chains and the generation of isolated Q(0) units, were observed at higher O/P ratios, which explained the nonlinear dependence of the optical properties on the O/P ratio.