Search results for "Self-induced transparency"

showing 3 items of 3 documents

Modulational instability and generation of self-induced transparency solitons in resonant optical fibers

2009

International audience; We consider continuous-wave propagation through a fiber doped with two-level resonant atoms, which is described by a system of nonlinear Schrodinger-Maxwell-Bloch (NLS-MB) equations. We identify the modulational instability (MI) conditions required for the generation of ultrashort pulses, in cases of both anomalous and normal GVD (group-velocity dispersion). It is shown that the self-induced transparency (SIT) induces non-conventional MI sidebands. The main result is a prediction of the existence of both bright and dark SIT solitons in the anomalous and normal GVD regimes.

Dark solitonOptical fiberNonlinear opticsElectromagnetic wave propagationWave propagationSelf-induced transparency01 natural sciencesDoped materialslaw.invention010309 opticsOpticslawVelocity dispersion0103 physical sciencesDispersion (optics)Optical solitonsGroup velocityOptical fibers010306 general physicsSelf-phase modulationNonlinear Sciences::Pattern Formation and SolitonsModulation instabilityTwo level atomPhysicsUltrashort pulsebusiness.industryNonlinear opticsSelf-phase modulationNonlinear equationsAtomic and Molecular Physics and Optics[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistryModulational instability[CHIM.THEO] Chemical Sciences/Theoretical and/or physical chemistry[ CHIM.THEO ] Chemical Sciences/Theoretical and/or physical chemistryGroup velocitySchroedinger equationLinear stabilitybusinessUltrashort pulse
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Field-free molecular alignment for probing collisional relaxation dynamics

2013

International audience; We report the experimental study of field-free molecular alignment in CO2 gas mixtures induced by intense femtosecond laser pulses in the presence of collisional processes. We demonstrate that the alignment signals exhibit specific features due to nontrivial collisional propensity rules that tend to preserve the orientation of the rotational angular momentum of the molecules. The analysis is performed with a quantum approach based on the modeling of rotational J- and M-dependent state-to-state transfer rates. The present work paves the way for strong-field spectroscopy of collisional dynamics.

PhysicsAngular momentumWork (thermodynamics)Field (physics)Mechanical effects of light on atoms molecules and ions42.50.MdRelaxation (NMR)Optical transient phenomena: quantum beats photon echo free-induction decay dephasings and revivals optical nutation and self-induced transparencyLaserMolecular physicsAtomic and Molecular Physics and Opticslaw.inventionRotational and vibrational energy transferlaw[SDU]Sciences of the Universe [physics]34.50.EzFemtosecond37.10.VzSpectroscopyQuantum
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A microscopic monomeric mechanism for interpreting intrinsic optical bistability observed in Yb3+-doped bromide materials

2004

We present a mechanism able to show intrinsic bistable behaviour involving single Yb3+ ions embedded into bromide lattices, in which intrinsic optical bistability (IOB) has been observed. The mechanism is based on the experimentally found coupling between the Yb3+ ion and the totally symmetric local mode of vibration of the [YbBr6]3- coordination unit. The model reproduces the IOB observed in CsCdBr3:1% Yb3+ and allows to understand the experimentally found presence of the phenomenon in the other bromides, but its absence in Cs3Lu2Cl9:Yb3+.

Solitons solitary waves self-induced transparencyMaterials sciencePhysics and Astronomy (miscellaneous)BistabilityDopingPhysics::OpticsAtomic and Molecular Physics and OpticsIonOptical bistabilityInterpretation (model theory)Coupling (electronics)chemistry.chemical_compoundMonomerchemistryChemical physicsBromide
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