FT-IR External Reflection Spectroscopy at Brewster's Angle

Abstract
A nondestructive technique for the measurement of infrared spectra of thick, hard, and dark materials has been studied with the use of external reflection spectroscopy. The distortion of the absorption bands which is due to optical effects can be minimized with the use of parallel polarized light which is incident at Brewster's angle. With this technique, it is impossible to observe over-absorption even if the material has a semi-infinite thickness. Also, this technique can be applied to the study of thin films on polymer substrates.