Tailoring the nonlinear refractive index of fluoride-phosphate glasses for laser applications

In this paper we report on measurements of the nonlinear refractive index n2 at 1047 nm of various fluoride-phosphate laser glasses relative to fused silica using degenerate four-wave mixing. We find good agreement with empirical estimates obtained from the d-line linear refractive index and the Abbe number for pure fluoride-phosphate glasses. Significant increase of n2 is observed when adding sulfate and niobium oxide to the glass composition offering tailorable nonlinear properties for glasses employed in short pulse laser oscillators.