Schott Sk7, 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	1.03745170E+00;
B2	5.04632691E-01;
B3	9.89114234E-01;
C1	5.37369046E-03;
C2	1.82926096E-02;
C3	1.02525987E+02;