Remarks on Observed Superluminal Light Propagation

L.J. Wang, A. Kuzmich, Arthur Dogariu

Yundong Zhang, Shuangqiang Liu, Hao Wu +2 more

Slow light and superluminal were both observed in Cs atomic vapor without any couple field. By only changing the signal modulate frequency, the light propagation changes from superluminal to slow light.

Phillip A. Sprangle, J. R. Peñano, B. Hafizi

Researchers claim to have observed superluminal (faster than light) propagation of a laser pulse in a gain medium by a new mechanism in which there is no distortion of the pulse [Nature, 406, 277 (2000)]. Our analysis shows that the observed mechanism is due to pulse distortion arising from a differential gain effect and should not be viewed as superluminal propagation.

Anedio Ranfagni, G. Viliani, C. Ranfagni +3 more

Robert W. Boyd, Matthew S. Bigelow, Nick N. Lepeshkin +2 more

We have observed ultraslow (57 m/s) propagation in ruby and superluminal (800 m/s) propagation in alexandrite enabled by the process of coherent population oscillations. Various novel applications are allowed by the ability to exercise such control on the velocity of light.

L. J. WANG