Schott Sk4, 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	1.39388834E+00;
B2	1.64510721E-01;
B3	9.63522479E-01;
C1	7.69147355E-03;
C2	2.71946227E-02;
C3	9.92757639E+01;