Rajaram B, Glandorf D L, Curtis D B, Tolbert M A, Toon O B, Ockman N
Appl Opt. 2001 Sep 1;40(25):4449-62. doi: 10.1364/ao.40.004449.
The optical constants of water ice have been determined in the near infrared from 4000 to 7000 cm(-1). Polycrystalline ice films with thickness as great as ~1164 mum were formed by condensation of water vapor on a cold silicon substrate at temperatures of 166, 176, 186, and 196 K. The transmission of light through the ice films was measured during their growth from 0 to 1164 mum over the frequency range of approximately 500-7000 cm(-1). The optical constants were extracted by means of simultaneously fitting the calculated transmission spectra of films of varying thickness to their respective measured transmission spectra with an iterative Kramers-Kronig technique. Equations are presented to account for reflection losses at the interfaces when the sample is held in a cell. These equations are used to reanalyze the transmission spectrum of water ice (358-mum sample at 247 K) recorded by Ockman in 1957 [Philos. Mag. Suppl. 7, 199 (1958)]. Our imaginary indices for water ice are compared with those of Gosse et al. [Appl. Opt. 34, 6582 (1995)], Kou et al. [Appl. Opt. 32, 3531 (1993)], Grundy and Schmitt [J. Geophys. Res. 103, 25809 (1998)], and Warren [Appl. Opt. 23, 1206 (1984)], and with the new indices from Ockman's spectrum. The temperature dependence in the imaginary index of refraction observed by us between 166 and 196 K and that between our data at 196 K and the data of Gosse et al. at 250 K are compared with that predicted by the model of Grundy and Schmitt. On the basis of this comparison a linear interpolation of the imaginary indices of refraction between 196 and 250 K is proposed. We believe that the accuracy of this interpolation is better than 20%.
已测定了水冰在4000至7000厘米⁻¹近红外波段的光学常数。通过在温度为166、176、186和196 K的冷硅衬底上冷凝水蒸气，形成了厚度达约1164微米的多晶冰膜。在冰膜从0生长到1164微米的过程中，测量了其在约500 - 7000厘米⁻¹频率范围内的光透射率。利用迭代的克拉默斯 - 克朗尼格技术，通过将不同厚度薄膜的计算透射光谱与各自测量的透射光谱同时拟合，提取出光学常数。给出了在样品置于样品池中时考虑界面反射损失的方程。这些方程用于重新分析奥克曼在1957年记录的水冰（247 K时358微米样品）的透射光谱[《哲学杂志增刊》7, 199 (1958)]。将我们得到的水冰虚折射率与戈斯等人[《应用光学》34, 6582 (1995)]、寇等人[《应用光学》32, 3531 (1993)]、格兰迪和施密特[《地球物理研究杂志》103, 25809 (1998)]以及沃伦[《应用光学》23, 1206 (1984)]的结果进行了比较，还与从奥克曼光谱得到的新折射率进行了比较。比较了我们在166至196 K观察到的虚折射率的温度依赖性以及我们在196 K的数据与戈斯等人在250 K的数据之间的温度依赖性与格兰迪和施密特模型预测的结果。基于此比较，提出了196至250 K之间虚折射率的线性插值。我们认为这种插值的精度优于20%。
