H-LAK10 by CDGM

$$n(\lambda) = \sqrt{1 + \frac{0.783175\,\lambda^2}{\lambda^2 - 0.00273169} + \frac{0.894315\,\lambda^2}{\lambda^2 - 0.0169034} + \frac{1.13897\,\lambda^2}{\lambda^2 - 111.159}}$$

$$\frac{dn}{dT} = \frac{n_0^2 - 1}{2\,n_0}\left[-9.18 \times 10^{-7} + 2(1.25 \times 10^{-8})\,\Delta T + 3(-2.28 \times 10^{-11})\,\Delta T^2 + \frac{4.91 \times 10^{-7} + 2(6.43 \times 10^{-10})\,\Delta T}{\lambda - 0.189}\right] \Delta T = T - T_0, \quad T_0 = 20\,°\text{C}$$