Spatio-temporal reshaping and X Wave dynamics in optical filaments.

Abstract

<p> <a href="http://oe.osa.org/virtual_issue.cfm?vid=36">Focus Serial: Frontiers of Nonlinear Optics</a> </p>We investigate ultrashort laser pulse filamentation within the framework of spontaneous X Wave formation. After a brief overview of the filamentation process we study the case of an intense filament co-propagating with a weaker seed pulse. The filament is shown to induce strong Cross-Phase-Modulation (XPM) effects on the weak seed pulse: driven by the pump, the seed pulse undergoes pulse splitting with the daughter pulses slaved to their pump counterparts. They undergo strong spatio-temporal reshaping and are transformed into XWaves traveling at the same group velocities as the pump split-off pulses. In the presence of a gain mechanism such as Four-Wave-Mixing or Stimulated Raman Scattering, energy is then transferred from the pump filament leading to amplification of the seed X Wave and formation of a temporally compressed intensity peak.

Ultraviolet-visible conical emission by multiple laser filaments

“…is the filament group velocity and α is a free fit parameter which accounts for the input conditions [33], which we set to zero in our curve. This is equivalent to considering ,…”

Laser pulse analogues for gravity and analogue Hawking radiation

“…An alternative route is based on a scattering model. The perturbation acts as a scattering defect and the scattered light will have a wave-vector k out (o) that is related to the input wave-vector k in (o IN ) by momentum conservation [45]: This momentum conservation relation may be transformed into the comoving frame using Equation (12) and leads to…”

Three-dimensional Spatiotemporal Accessible Solitons in a PT-symmetric Potential

“…We assume N to be of the form           ′   ′  ′ , where    is the normalized symmetric real response function of the medium whose characteristic length determines the degree of nonlocality. The setting chosen in this paper is reminiscent of the X wave generation geometry [24]; the wave equations are similar and there exist natural linear and nonlinear regimes of wave packet dynamics. The major difference is that we consider a nonlocal medium with anomalous dispersion.…”