Abstract
The temporal evolution of the width and shift of N I 746.8 and O I 777.4nm lines is investigated in a filament plasma produced by a tightly focused femtosecond laser pulse (0.9mJ, 48fs). The nitrogen line shift and width are determined by the joint action of electron impact shift and the far-off resonance AC Stark effect. The intensive (I=1.2·1010W/cm2) electric field of ASE (amplified spontaneous emission) and post-pulses result in a possible LS coupling break for the O I 3p 5P level and the generation of Rabi sidebands. The blueshifted main femtosecond pulse and Rabi sideband cause the stimulated emission of the N2 1+ system. The maximal widths of emission lines are approximately 6.7 times larger than the calculated Stark widths.
Published Version
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