Elimination, reversal, and directional bias of optical diffraction

TL;DR

This paper demonstrates how atomic thermal motion in a hot vapor medium can be used to control optical diffraction, enabling elimination, reversal, and directional bias of diffraction effects for arbitrary images.

Contribution

It introduces a novel method to manipulate optical diffraction using EIT in hot vapor, including elimination and reversal of diffraction effects.

Findings

Diffraction can be completely eliminated for arbitrary images.

Diffraction can be doubled or biased asymmetrically.

An analogy to a negative-index lens is experimentally realized.

Abstract

We experimentally demonstrate the manipulation of optical diffraction, utilizing the atomic thermal motion in a hot vapor medium of electromagnetically-induced transparency (EIT). By properly tuning the EIT parameters, the refraction induced by the atomic motion may completely counterbalance the paraxial free-space diffraction and by that eliminates the effect of diffraction for arbitrary images. By further manipulation, the diffraction can be doubled, biased asymmetrically to induced deflection, or even reversed. The latter allows an experimental implementation of an analogy to a negative-index lens.