Negative Group Velocity
Optics
2009-11-06 v4
Abstract
The group velocity for pulses in an optical medium can be negative at frequencies between those of a pair of laser-pumped spectral lines. The gain medium then can amplify the leading edge of a pulse resulting in a time advance of the pulse when it exits the medium, as has been recently demonstrated in the laboratory. This effect has been called superluminal, but, as a classical analysis shows, it cannot result in signal propgation at speeds greater than that of light in vacuum.
Keywords
Cite
@article{arxiv.physics/0008013,
title = {Negative Group Velocity},
author = {Kirk T. McDonald},
journal= {arXiv preprint arXiv:physics/0008013},
year = {2009}
}
Comments
v3 adds discussion of "rephasing", and adds a figure. v4 adds references to the early history of negative group velocity, and adds a figure; thanks to Alex Granik