Physical realization of Photonic Klein Tunneling

TL;DR

This paper investigates the physical conditions enabling photonic Klein tunneling, emphasizing the role of spontaneous emission, and provides an analytical example demonstrating how reflection can be arbitrarily large despite suppressed transmission.

Contribution

It offers a detailed analytical study of photonic Klein tunneling in dielectric slabs, highlighting the impact of spontaneous emission on reflection and transmission probabilities.

Findings

Reflection probability can be arbitrarily large at certain wavelengths.

Transmission can be exponentially suppressed while reflection remains high.

Spontaneous emission influences photonic tunneling behavior.

Abstract

General physical conditions for the occurrence of photonic Klein tunneling are studied, where (controlled) spontaneous emission from the devices considered plays a key role. The specific example of a simple dielectric slab bounded by two dielectric half spaces with arbitrary refractive indices is worked out quite in detail, the measured reflection and transmission probabilities being calculated analytically. It is found that, in given cases, the measured reflection probability may be arbitrarily large (for large incident wavelengths) irrespective of the fact that the transmission probability is exponentially suppressed or not. Other interesting features of photonic Klein tunneling driven by (controlled) spontaneous emission are as well envisaged for practical applications.