Altitude-Dependent Laser Filamentation and High-Voltage Discharge Guidance in Atmospheric Air

Air ionization induced by ultrashort pulsed lasers represents a key mechanism for guiding electrical discharges in atmospheric environments. In this study, the physical feasibility of laser-induced plasma channel formation at flight altitudes of ۱۰, ۱۵, and ۲۰ km is quantitatively analyzed based on filamentation scaling laws and the standard atmospheric model. The critical self-focusing power, required peak power, pulse energy, and ionized channel stability are estimated as functions of air density and altitude-dependent atmospheric parameters. The results indicate that decreasing air density at higher altitudes reduces both the ionization threshold and the critical self-focusing power, leading to lower peak power requirements for filament formation. However, this reduction is accompanied by a decrease in effective plasma channel length and stability due to the diminished nonlinear Kerr coefficient and increased sensitivity to atmospheric perturbations. The analysis reveals the existence of an altitude-dependent trade-off between ionization initiation efficiency and the spatiotemporal robustness of the discharge-guiding channel. The feasibility of generating a quasi-persistent ionized channel using high-repetition-rate pulsed lasers is also examined. Although each filament is inherently transient on microsecond timescales, successive pulses can effectively sustain enhanced conductivity over longer durations. Within this framework, a conceptual non-kinetic protective approach is proposed, in which controlled modification of the local electromagnetic environment surrounding an airborne platform may reduce the probability of successful engagement by lightweight aerial threats, without relying on destructive interception mechanisms. Overall, the findings demonstrate that laser-induced air ionization at flight altitudes is physically achievable within defined operational regimes, while its practical implementation is strongly constrained by altitude-dependent nonlinear atmospheric parameters, plasma recombination dynamics, and system-level limitations. These results establish altitude-dependent operational boundaries for high-voltage discharge guidance and provide a quantitative foundation for future experimental validation and advanced numerical modeling.

کلیدواژه ها:

Laser Filamentation ، Air Ionization ، High-Voltage Discharge Guidance ، Nonlinear Atmospheric Optics ، Nonlinear Wave Propagation in Air