Coherent population trapping (CPT) versus electromagnetically induced transparency (EIT)

TL;DR

This paper compares coherent population trapping (CPT) and electromagnetically induced transparency (EIT), highlighting their differences through experiments involving rubidium vapor cells and various parameters affecting the phenomena.

Contribution

It provides an experimental analysis of the differences between CPT and EIT, focusing on effects like power, detuning, and buffer gas in rubidium vapor.

Findings

Power affects CPT and EIT differently

Detuning influences the phenomena distinctly

Buffer gas impacts the coherence properties

Abstract

We discuss the differences between two well-studied and related phenomena---coherent population trapping (CPT) and electromagnetically induced transparency (EIT). Many differences between the two---such as the effect of power in the beams, detuning of the beams from resonance, and the use of vapor cells filled with buffer gas---are demonstrated experimentally. The experiments are done using magnetic sublevels of the $ 1 \rightarrow 1 $ transition in the D$_2$ line of $^{87}$Rb.