Phase modulation induced by cooperative effects in electromagnetically induced transparency

TL;DR

This paper investigates how dipole-dipole interactions at high density affect phase modulation in electromagnetically induced transparency, revealing a local field effect distinct from Kerr nonlinearities.

Contribution

It provides an analytical and numerical analysis of local field induced phase modulation due to dipole interactions in EIT, highlighting a novel effect.

Findings

Dipole-dipole interactions modulate the phase of a weak pulse in EIT.

The phase modulation is distinct from Kerr self-phase modulation.

The effect is explained through an intuitive local field perspective.

Abstract

We analyze the influence of dipole-dipole interactions in an electromagnetically induced transparency setup at high density. We show both analytically and numerically that the polarization contribution to the local field strongly modulates the phase of a weak pulse. We give an intuitive explanation for this local field induced phase modulation and show that it distinctively differs from the nonlinear self-phase modulation a strong pulse experiences in a Kerr medium.