Schott LaK 21, 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	1.22718116E+00;
B2	4.20783743E-01;
B3	1.01284843E+00;
C1	6.02075682E-03;
C2	1.96862889E-02;
C3	8.84370099E+01;