Schott SSK 51, 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	1.44260939E+00;
B2	8.28623622E-02;
B3	8.92805443E-01;
C1	8.90475064E-03;
C2	4.00883477E-02;
C3	1.03152733E+02;