Theory of Thermal Motion in Electromagnetically Induced Transparency: Diffusion, Doppler, Dicke and Ramsey

TL;DR

This paper develops a comprehensive theoretical model for electromagnetically induced transparency (EIT) in vapor, accounting for atomic motion, collisions, and various motional effects that influence EIT spectra and light storage.

Contribution

It introduces a unified formalism that incorporates atomic motion and collisions into EIT dynamics, explaining multiple motional effects observed in vapor-based EIT.

Findings

Doppler-broadening of absorption spectrum

Dicke-narrowing and time-of-flight broadening of transmission window

Diffusion effects during light storage and slow-light propagation

Abstract

We present a theoretical model for electromagnetically induced transparency (EIT) in vapor, that incorporates atomic motion and velocity-changing collisions into the dynamics of the density-matrix distribution. Within a unified formalism we demonstrate various motional effects, known for EIT in vapor: Doppler-broadening of the absorption spectrum; Dicke-narrowing and time-of-flight broadening of the transmission window for a finite-sized probe; Diffusion of atomic coherence during storage of light and diffusion of the light-matter excitation during slow-light propagation; and Ramsey-narrowing of the spectrum for a probe and pump beams of finite-size.