Self-Guiding without Focusing Nonlinearity: Leaking Mode Self-Effect Due to Field-Induced Saturable Ionization

Effect of plasma-core-induced self-guiding on phase matching of high-order harmonic generation in gases

“…The observation that ionization has a dominant role in this type of guiding is in agreement with the previous finding that qualitatively the same steady-state results can be obtained when no focusing nonlinearity is considered in the model (η 2 = η2 = 0) [23,51]. This type of laser guiding [36], also called "ionization-induced leaking-mode channeling" in previous work [24,25], has several interesting features and consequences on HHG. In the following few paragraphs we present the results of several numerical simulations, which were carried out with different input conditions.…”

“…At the same time, it is less often highlighted that for short pulses the rapid ionization can play a leading role in the guiding of a laser beam by the formation of a self-sustained plasma filament [22][23][24][25][26][27][28][29]. Plasma-core induced beam self-guiding has been studied up to now in the context of beam smoothing [30], frequency shifts [31] or other pulse propagation-related phenomena [28,32], but only a few times mentioned in relation to HHG in gases [29,[33][34][35][36][37].…”