Slow light of an amplitude modulated Gaussian pulse in electromagnetically induced transparency medium

TL;DR

This paper investigates the slow light behavior of amplitude modulated Gaussian pulses in an EIT medium, revealing distortion causes and proposing a compensation method to improve pulse shape and achieve simultaneous slow and fast light.

Contribution

It introduces a compensation technique based on transmission spectrum to reduce distortion of AMG pulses in EIT media and demonstrates a novel method for achieving simultaneous slow and fast light.

Findings

Distortion is mainly caused by linear absorption, not dispersion.

A compensation method effectively reshapes the slow light pulse.

Simultaneous slow and fast light can be realized in the medium.

Abstract

The slow light effects of an amplitude modulated Gaussian (AMG) pulse in a cesium atomic vapor are presented. In a single-$\Lambda$ type electromagnetically induced transparency (EIT) medium, more severe distortion is observed for an AMG pulse than a Gaussian one. Using Fourier spectrum analysis, we find that the distortion, as well as the loss, is dominantly caused by linear absorption than dispersion. Accordingly, a compensation method is proposed to reshape the slow light pulse based on the transmission spectrum. In addition, we find a novel way to obtain simultaneous slow and fast light.