Non-diffracting Optical Beams in a Three-level Raman System

TL;DR

This paper demonstrates that using a three-level Raman atomic system with a control beam can enable diffractionless propagation of various optical modes, including complex images, through warm atomic vapors over long distances.

Contribution

It introduces a method to achieve non-diffracting optical beams in atomic vapors using a tailored control beam in a three-level Raman configuration, enabling propagation of complex modes.

Findings

Diffractionless propagation of Gaussian and non-Gaussian modes demonstrated.

Laguerre-Gaussian control beam enables long-distance image propagation.

Potential for transmitting arbitrary images through warm atomic vapors.

Abstract

Diffractionless propagation of optical beams through atomic vapors is investigated. The atoms in the vapor are operated in a three-level Raman configuration. A suitably chosen control beam couples to one of the transitions, and thereby creates a spatially varying index of refraction modulation in the warm atomic vapor for a probe beam which couples to the other transition in the atoms. We show that a Laguerre-Gaussian control beam allows to propagate single Gaussian probe field modes as well as multi-Gaussian modes and non-Gaussian modes over macroscopic distances without diffraction. This opens perspectives for the propagation of arbitrary images through warm atomic vapors.