High-frequency Light Reflector via Low-frequency Light Control

TL;DR

This paper demonstrates that atomic coherence induced by low-frequency light can reverse the momentum of high-frequency light, enabling controllable reflection and photon retrieval with potential applications in X-ray optics.

Contribution

It introduces a novel method to control high-frequency light reflection using low-frequency light-induced atomic coherence, expanding possibilities for light manipulation.

Findings

Reversal of light momentum via atomic coherence.

Analysis of photon retrieval from timed Dicke states.

Proposal of experiments with rubidium atoms and beryllium ions.

Abstract

We show that the momentum of light can be reversed via the atomic coherence created by another light with one or two orders of magnitude lower frequency. Both the backward retrieval of single photons from a timed Dicke state and the reflection of continuous waves by high-order photonic band gaps are analysed. The required control field strength scales linearly with the nonlinearity order, which is explained by the dynamics of superradiance lattices. Experiments are proposed with $^{85}$Rb atoms and Be$^{2+}$ ions. This holds promise for light-controllable X-ray reflectors.