Four Techniques to Measure Complex Refractive Indices of Liquids and Solids at Carbon Dioxide Laser Wavelengths in the Infrared Spectral Region

Four techniques were developed to determine the optical constants of liquids and solids. Two cells were designed and constructed to obtain the optical constants of liquids, a wedge-shaped cell and an internal reflectance cell. The wedge-shaped cell was used to determine the optical constants of 11 liquids in the spectral range 500-12500 cm-1. The techniques of Querry and Avery were used in conjunction with the internal reflectance cell to obtain the complex refractive index of water and SF-96. The complex refractive indices of illite, kaolin, and montmorillinite were obtained from applying the techniques of Querrys and Averys. The error associated with each of the four techniques was also examined and is summarized. Keywords Absorption, Reflectance, Optical constants, Refractive indices, Carbon dioxide laser, Infrared.