S-LAL11 by Ohara

$$n(\lambda) = \sqrt{2.70375 - 0.0117419\,\lambda^2 + 0.0158996\,\lambda^{-2} + 0.000612654\,\lambda^{-4} - 4.66768 \times 10^{-5}\,\lambda^{-6} + 2.6545 \times 10^{-6}\,\lambda^{-8}}$$

$$\frac{dn}{dT} = \frac{n_0^2 - 1}{2\,n_0}\left[-6.19 \times 10^{-7} + 2(1.33 \times 10^{-8})\,\Delta T + 3(-4.63 \times 10^{-11})\,\Delta T^2 + \frac{6.45 \times 10^{-7} + 2(4.57 \times 10^{-10})\,\Delta T}{\lambda - 0.178}\right] \Delta T = T - T_0, \quad T_0 = 25\,°\text{C}$$