Temperature interpolation of the optical constants for sample X35. The two upper panels show the comparison of k (upper left) and n (upper right) calculated from the measurements at 10, 100, 200, and 300 K (blue, green, orange, and red curves, respectively) with the interpolated ones (black dashed lines) together with their associated error. The two lower panels show k (lower left) and n (lower right) at temperatures from 10 K to 300 K. The interpolated optical constants are shown by the dashed lines and those calculated from measurements are the continuous lines.