Superluminal optical pulse propagation in nonlinear coherent media

Journal Article · Sun Jun 01 04:00:00 EDT 2003 · Physical Review. A

DOI:https://doi.org/10.1103/PhysRevA.67.063806· OSTI ID:20639814

Ghulghazaryan, Ruben G ^[1]; Malakyan, Yuri P ^[2]

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1. Department of Theoretical Physics, Yerevan Physics Institute, Alikhanian Brothers 2, 375036 Yerevan, (Armenia)
2. Institute for Physics Research, Armenian National Academy of Sciences, Ashtarak-2, 378410, (Armenia)

We investigate a light-pulse propagation with negative group velocity in a nonlinear coherent medium. We show that the necessary conditions for nonlinear superluminal effects to be observable are realized in a three-level {lambda} system interacting with a linearly polarized laser field in the presence of a static magnetic field. The initially prepared Zeeman coherence cancels the resonant absorption of the medium almost completely, but preserves its dispersion anomalous and very high. In this medium the light pulse propagates superluminally in the sense that the peak of the transmitted pulse exits the medium before the peak of the incident pulse enters. At the same time the pulse group velocity is intensity dependent, which leads to the self-steepening of the pulse trailing edge due to the fact that the more intense parts of the pulse travel slower. This is in contrast with the shock wave generation in a nonlinear medium with normal dispersion. The predicted effect can be easily observed in the well-known schemes employed in the studies of nonlinear magneto-optical rotation. The upper bound of sample length is found from the criterion that the pulse self-steepening and group-advance time are observable without pulse distortion caused by the group-velocity dispersion.

• OSTI ID: 20639814
• Journal Information: Physical Review. A, Journal Name: Physical Review. A Journal Issue: 6 Vol. 67; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
ABSORPTION
LASER RADIATION
LIGHT TRANSMISSION
MAGNETIC FIELDS
MAGNETO-OPTICAL EFFECTS
NONLINEAR OPTICS
NONLINEAR PROBLEMS
OPTICAL DISPERSION
PULSES
QUANTUM MECHANICS
ROTATION
SHOCK WAVES
VELOCITY
VISIBLE RADIATION
ZEEMAN EFFECT