Gain-assisted superluminal light propagation via incoherent pump field

TL;DR

This paper demonstrates how an incoherent pump field can control light's group velocity in a three-level atomic system, enabling gain-assisted superluminal propagation without laser pumping.

Contribution

It introduces a method to achieve superluminal light propagation using only incoherent pumping, avoiding the need for laser fields in the process.

Findings

Dispersion slope switches from positive to negative with pump intensity.

Superluminal light propagation is achieved with gain assistance.

No laser field is required for the pumping process.

Abstract

We investigate the dispersion and the absorption properties of a weak probe field in a three-level Lambda-type atomic system. We use just an incoherent field for controlling the group velocity of light. It is shown that the slope of dispersion changes from positive to negative just with changing the intensity of the indirect incoherent pumping field. Gain-assisted superluminal light propagation appears in this system. No laser field is used in the pumping processes.