Anomalous ring-down effects and breakdown of the decay rate concept in optical cavities with negative group delay

作者：Laupretre T; Schwartz S; Ghosh R; Carusotto I; Goldfarb F; Bretenaker F^*

来源：New Journal of Physics, 2012, 14: 043012.

DOI：10.1088/1367-2630/14/4/043012

The propagation of light pulses through negative group velocity media is known to give rise to a number of paradoxical situations that seem to violate causality. The solution of these paradoxes has triggered the investigation of a number of interesting and unexpected features of light propagation. Here, we report a combined theoretical and experimental study of the ring-down oscillations in optical cavities filled with a medium with a sufficiently negative frequency dispersion to give a negative round-trip group delay time. We theoretically anticipate that causality imposes the existence of additional resonance peaks in the cavity transmission, resulting in a non-exponential decay of the cavity field and in a breakdown of the cavity decay rate concept. Our predictions are validated by simulations and by an experiment using a room-temperature gas of metastable helium atoms in the detuned electromagnetically induced transparency regime as the cavity medium.

• 出版日期2012-4-13