H-ZF7LAGT by CDGM

$$n(\lambda) = \sqrt{1 + \frac{1.65846\,\lambda^2}{\lambda^2 - 144.875} + \frac{0.298796\,\lambda^2}{\lambda^2 - 0.0635425} + \frac{1.81848\,\lambda^2}{\lambda^2 - 0.0141908}}$$

$$\frac{dn}{dT} = \frac{n_0^2 - 1}{2\,n_0}\left[-7.91 \times 10^{-6} + 2(1.24 \times 10^{-8})\,\Delta T + 3(-3.12 \times 10^{-11})\,\Delta T^2 + \frac{1.09 \times 10^{-6} + 2(1.48 \times 10^{-9})\,\Delta T}{\lambda - 0.281}\right] \Delta T = T - T_0, \quad T_0 = 20\,°\text{C}$$