Maximal refraction and superluminal propagation in a gaseous nanolayer
Atomic Physics
2012-12-06 v1 Optics
Abstract
We present an experimental measurement of the refractive index of high density Rb vapor in a gaseous atomic nanolayer. We use heterodyne interferometry to measure the relative phase shift between two copropagating laser beams as a function of the laser detuning and infer a peak index n = 1.26 \pm 0.02, close to the theoretical maximum of 1.31. The large index has a concomitant large index gradient creating a region with steep anomalous dispersion where a sub-nanosecond optical pulse is advanced by >100 ps over a propagation distance of 390 nm, corresponding to a group index of -1x10^5, the largest negative group index measured to date.
Keywords
Cite
@article{arxiv.1208.4309,
title = {Maximal refraction and superluminal propagation in a gaseous nanolayer},
author = {J. Keaveney and I. G. Hughes and A. Sargsyan and D. Sarkisyan and C. S. Adams},
journal= {arXiv preprint arXiv:1208.4309},
year = {2012}
}