--- /dev/null
+Schott BaLK N3, 313nm - 2325nm\r
+USER\r
+2 1\r
+SQRT(1+B1*wvl^2/(wvl^2-C1)+B2*wvl^2/(wvl^2-C2)+B3*wvl^2/(wvl^2-C3))\r
+0\r
+B1 1.116317e+000\r
+C1 6.841098e-003\r
+B2 1.572606e-001\r
+C2 2.570488e-002\r
+B3 9.140297e-001\r
+C3 1.059192e+002\r