Effect of Injected Noise on Electromagnetically Induced Transparency and Slow Light

TL;DR

This paper theoretically investigates how externally injected classical noise affects Electromagnetically Induced Transparency (EIT) and slow light in a three-level atomic system, revealing that noise reduces transparency and slow-down effects.

Contribution

It introduces a theoretical analysis of classical injected noise impact on EIT and slow light, highlighting differences from quantum noise effects.

Findings

Injected noise broadens and reduces EIT transparency

Noise decreases the slowing of group velocity of probe light

Classical noise is not canceled by EIT, unlike quantum noise

Abstract

We have examined theoretically the phenomenon of Electromagnetically Induced Transparency (EIT) in a three-level system operating in the lambda-configuration in presence of an externally injected noise coupling the ground level to the intermediate (metastable) level. The changes in the depth and the width of the induced transparency and the slowing down of the probe light have been calculated as function of the probe detuning and the strength of the injected noise. The calculations are within the rotating-wave approximation (RWA). Our main results are the reduction and the broadening of the EIT with increasing strength of the injected noise, and a reduction in the slowing down of group velocity of the probe-laser beam. Thus, the injected semi-classical noise, unlike the quantum-dynamical noise associated with the spontaneous emission, is not effectively cancelled by the EIT mechanism.