Refractive indices of water and ice in the 0.65- to 2.5-µm spectral range

New accurate values of the imaginary part, k, of the refractive index of water at 22 C, supercooled water at -8 C and polycrystalline ice at -25 C are reported. The k spectrum for water in the spectral region 0.65-2.5 microns is found to be in excellent agreement with those of previous studies. The k values for polycrystalline ice in the 1.44-2.50-micron region eliminate the large uncertainties existing among previously published conflicting sets of data. The imaginary part of refractive index of supercooled water shows a systematic shift of absorption peaks toward the longer wavelengths compared with that of water at warmer temperatures.