Attenuated Total and Internal Reflection Correction Based on Fresnel's Equations: Beyond the Low Absorption Assumption.

Some attenuated total reflection (ATR) correction formalisms share the drawback that they can only be applied to materials with relatively low oscillator strength, as they rely on one or another form of the low absorption assumption. In this contribution, we present an iterative formalism that does not suffer from this limitation and can be applied not only to attenuated total reflection spectra but also to spectra acquired under internal reflection conditions at subcritical incidence angles. Its accuracy is primarily limited near the critical angle and Brewster's angle. The formalism is based on the perpendicular component of the wavevector and Fresnel's equations, and it is fully compatible with wave optics. Its application is straightforward, and a corresponding program is available via the Supplemental Material.