Palmer K F, Williams D
Appl Opt. 1975 Jan 1;14(1):208-19. doi: 10.1364/AO.14.000208.
With the purpose of obtaining the real and imaginary parts of the complex refractive index N; = n + ik, we have made quantitative measurements of spectral transmission and reflection of sulfuric acid solutions in the visible and near infrared. On the basis of the results, we have obtained values for n throughout the entire region and values of k in the near infrared together with upper limits for k in the visible region. These optical constants can be used to interpret the results of polarization studies of solar radiation that has been scattered by the clouds of Venus. We have Kramers-Kronig phase-shift analysis to obtain values of n and k from reflection measurements in the intermediate infrared region (400-4000 cm(-1)). Our measurements were made at 300 K on sulfuric acid solutions having concentrations by weight of 95.6, 84.5, 75, 50, 38, and 25%. If the particles in the Venus clouds consist of liquid droplets of sulfuric acid at a temperature of 250 K, comparison of existing Venus data with our data suggests that the acid concentration is probably higher than 70%. Various possibilities are discussed.
为了获得复折射率(N = n + ik)的实部和虚部，我们对硫酸溶液在可见光和近红外波段的光谱透过率和反射率进行了定量测量。基于这些结果，我们得到了整个区域的(n)值以及近红外区域的(k)值，同时还得到了可见光区域(k)的上限。这些光学常数可用于解释被金星云层散射的太阳辐射的偏振研究结果。我们利用克拉默斯 - 克勒尼希相移分析从中间红外区域（(400 - 4000 cm^{-1})）的反射测量中获取(n)和(k)的值。我们在(300K)下对重量浓度分别为(95.6%)、(84.5%)、(75%)、(50%)、(38%)和(25%)的硫酸溶液进行了测量。如果金星云层中的粒子由温度为(250K)的硫酸液滴组成，将现有的金星数据与我们的数据进行比较表明，酸浓度可能高于(70%)。文中讨论了各种可能性。
