Femtosecond Filamentation in Air

Femtosecond filamentation in transparent media

“…The beam radius R(z), the maximum intensity (solid curve, left axis), the density of free electrons on-axis (dashed curve, right axis) and the fluence distribution are plotted as a function of the propagation distance. According to Couairon and Mysyrowicz (2006).…”

“…Moloney and Kolesik, 2007;Couairon and Mysyrowicz, 2006;Chin et al, 2005, for a review). The first numerical simulations in this field started with a minimal model in the form of a nonlinear Schrödinger equation describing the pulse propagation and catching the essential of the physics without developing heavy numerical tools.…”

“…The initial pulse (a) undergoes contraction in the transverse diffraction plane (b) plasma defocusing of its trailing part (c) which is subsequently refocused by the optical Kerr effect (apparent splitting beyond the nonlinear focus) (d,e,f) During the propagation in the form of a filament, successive focusing-defocusing cycles reinforce and accentuate the shortening and the stiffening of the pulse beyond the nonlinear focus. From Couairon and Mysyrowicz (2006). trail of the pulse and its subsequent refocusing by the optical Kerr effect.…”

“…22. From Couairon and Mysyrowicz (2006). (c) The power spectra of a filamented pulse at 1.1 Rayleigh lengths are compared in the absence (continuous curve) and in the presence (dashed curve) of self-steepening.…”

Experimental Investigation of Linear Energy Deposition Using Femtosecond Laser Filamentation in a M=3 Supersonic Flow.

“…Recently, as a way to improve the interaction time and reduce the repetition frequency, it has been suggested to use elongated and linear energy deposition [15]- [18]. This idea is guided by the recent progress of femtosecond lasers, which are known to create thin ionized channels [12] [13] [19]. These channels can be used to guide an electric discharge and there is currently an ongoing research effort to couple more energy to this ionized channel using various mechanisms (more powerful nanosecond lasers [21], pulsed discharges or microwave excitation [22]).…”