Schott Sk18A, 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	1.53857004E+00;
B2	9.85934131E-02;
B3	1.02309528E+00;
C1	8.63201486E-03;
C2	3.67156464E-02;
C3	1.00118441E+02;