EIT enhancement in a Doppler broadened medium

Electromagnetically induced transparency (EIT) is the fact that a strong field (called control) resonant with an atomic transition, can make the atomic medium transparent for another field (called signal) resonant with a transition sharing the same excited state. Introduced theoretically and first observed by Harris and co-workers, it has since then given rise to important applications. Significantly, EIT led to the demonstration of slow-light and opened the way to the development of a reversible quantum memory for light, which is a major challenge for quantum information networking.