Superfilament Spatial Dynamics and Energy Deposition under Various Focusing Conditions

Summary form only given. One of the distinctive features of femtosecond laser filamentation is intensity and plasma concentration clamping. Arising due to the dynamical competition between Kerr focusing and plasma defocusing this phenomenon limits the peak intensity to the values 10
¹⁴
W/cm
²
and plasma concentration level to 10
¹⁶
-10
¹⁷
cm
^-3
. Further increase of the beam power leads to the beam splitting and multifilament formation rather than to an intense single filament with high plasma density. However it have been recently shown that fusing several filaments by introducing additional weak focusing one can obtain significant enhancement of energy deposition in the extended region around the focus resulting in higher plasma concentration and intensity [1,2,3]. This report aims to present the comprehensive picture of superfilament evolution including its formation from merging fi laments and dissipation stages. We discuss energy deposition during the multifilament evolution and its dependency of the pulse energy as well as the influence of additional focusing conditions on superfilament formation.