Schott SSK 50, 365nm - 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	1.45562999E+00;
B2	1.13575966E-01;
B3	9.69520910E-01;
C1	8.70103680E-03;
C2	3.78429476E-02;
C3	1.10109218E+02;