The Optical Properties of Liquids, Metals, and Minerals in the Far-Infrared

The development of a method for obtaining the optical properties in the far infrared for liquids is presented as well as using established methods to determine the optical properties of specific metals and a mineral. The liquids studied were diesel fuel and dimethyl methylphosphonate. The metals were vanadium, cobalt, and stainless steel 316L. The mineral was zinc oxide. These materials were chosen because they are of interest to the United States Army. The transmittance of the liquids was measured from which the absorption coefficient and imaginary part of the index of refraction could be obtained. The normalized surface resistance of the metals was measured. Using Kramers-Kronig analysis, the normalized surface reactance was obtained from which the complex index of refraction and the complex dielectric function were determined. The reflectivity of the mineral was measured. Using an oscillator fit model, the oscillator parameters could be obtained from which the complex index of refraction and the complex dielectric function were determined.