Schott SSK 3, 334nm - 2325nm
USER
2 1
SQRT(1+B1*wvl^2/(wvl^2-C1)+B2*wvl^2/(wvl^2-C2)+B3*wvl^2/(wvl^2-C3))
0
B1	1.39915758E+00;
B2	1.58923825E-01;
B3	9.91912922E-01;
C1	8.28660770E-03;
C2	3.54515342E-02;
C3	1.15227785E+02;