Beneath and beyond frustrated total reflection: a practical demonstration

TL;DR

This paper presents a practical demonstration of frustrated total internal reflection, using incident angles as the scanning variable, with a theoretical framework and an undergraduate experiment measuring light reflection and transmission.

Contribution

It introduces a novel perspective by analyzing incident angles instead of film thickness and provides an accessible experiment for educational purposes.

Findings

Experimental results align with theoretical predictions

Reflection and transmission measurements demonstrate frustrated total internal reflection

The approach enhances understanding of optical phenomena in educational settings

Abstract

Frustrated total internal reflection is analyzed from an unusual point of view Unlike most similar works, incident angles are used here as the scanning variable, instead of the tunneled film thickness. The theoretical framework is presented defining our own normalized variables, better adapted to the problem at hand. A straightforward and captivating experiment, appropriate for undergraduate classroom demonstrations is also presented. The experiment involves measuring the reflection and transmission of light through a pair of prisms separated by an air or water layer, and the results are in fair agreement with theory.