Enhanced Deflection of Light Ray by Atomic Ensemble on Coherent Population Oscillation

TL;DR

This paper investigates a novel mechanism based on coherent population oscillation for enhancing light deflection in atomic ensembles, differing from previous EIT-based methods, and demonstrates how a spatially varying control beam causes probe light bending.

Contribution

It introduces a new deflection mechanism using coherent population oscillation in two-level atoms, expanding understanding beyond EIT-based approaches.

Findings

Signal ray bends due to spatial control beam profile

Response analyzed under large detuning with steady state approximation

Enhanced light deflection achieved via coherent population oscillation

Abstract

In recent experiments[e.g., Nature Physics 2, 332 (2006)], the enhanced light deflection in an atomic ensemble due to inhomogeneous fields is demonstrated by the electromagnetically induced transparency (EIT) based mechanism. In this paper, we explore an different mechanism for the similar phenomenon of the enhanced light deflection. This mechanism is based on the coherent population oscillation, which leads to the hole burning in the absorption spectrum. The medium causing the deflection of probe light is an ensemble of two-level atoms manipulated by a strong controlled field on the two photon resonances. In the large detuning condition, the response of the medium to the pump field and signal field is obtained with steady state approximation. And it is found that after the probe field travels across the medium, the signal ray bends due to the spatial-dependent profile of the control beam.