Radiation trapping under conditions of electromagnetically induced transparency

Abstract

Reabsorption of spontaneously emitted photons, or radiation trapping, is a process that occurs when light interacts with optically thick media. It is shown, both theoretically and experimentally, that this effect in optically thick atomic vapour leads to a decrease in transmission of coherent laser radiation propagating under conditions of electromagnetically induced transparency (EIT). A simple theory is developed taking into account the radiation trapping, which is in a good agreement with the experimental observations and exact numerical simulation. This allows better understanding of the physics of EIT in general, and properties of dense coherent atomic media in particular.