Negative Group Velocity

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.

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

References in corpus (1)

• Slow light

Cited by in corpus (8)

• Superradiant Amplification of Acoustic Beams via Medium Rotation
• Effects of Schwarzschild Black Hole Horizon on Isothermal Plasma Wave Dispersion
• On mediums with negative phase velocity: a brief overview
• An Electrostatic Wave
• Negative group velocity and Kelvin-like wake pattern
• The fundamentals of harnessing the magneto-optics of quantum wires for designing optical amplifiers: Formalism
• Splashes in isotropic media
• Magnetic influence on classical dispersion