H-ZLAF90 by CDGM

$$n(\lambda) = \sqrt{1 + \frac{0.494167\,\lambda^2}{\lambda^2 - 0.0602358} + \frac{2.31375\,\lambda^2}{\lambda^2 - 0.0137149} + \frac{2.2793\,\lambda^2}{\lambda^2 - 148.088}}$$

$$\frac{dn}{dT} = \frac{n_0^2 - 1}{2\,n_0}\left[-2.2 \times 10^{-6} + 2(1.4 \times 10^{-8})\,\Delta T + 3(-1.91 \times 10^{-11})\,\Delta T^2 + \frac{1.04 \times 10^{-6} + 2(1.38 \times 10^{-9})\,\Delta T}{\lambda - 0.29}\right] \Delta T = T - T_0, \quad T_0 = 20\,°\text{C}$$