Fig. 1. Layout of laser electrical characteristic experiment

Fig. 2. Relationship between loop current amplitude and applied electric field between plates

Fig. 3. Relationship between loop current amplitude and laser energy

Fig. 4. Relationship between loop current amplitude and x_L under 1 m focal length lens

Fig. 5. Cross section views of femtosecond laser filaments. (a) Distance from focusing lens is 4.95 m; (b) distance from focusing lens is 5.18 m

Fig. 6. Relationship between loop current amplitude and x_L under 5 m focal length lens

Fig. 7. Equivalent circuit model of filament electrical characteristics experiment

Fig. 8. Comparison between simulated waveform and measured waveform

Fig. 9. Relationship between sampling resistance waveform and filament equivalent resistance

Fig. 10. Relationship between loop current amplitude and filament equivalent resistance

Fig. 11. Relationship between equivalent resistance of filament and x_L