Few-cycle optical pulse production from collimated femtosecond laser beam filamentation

Single-cycle pulse generation in the course of four-wave mixing in the filament

“…2). This results are in a good agreement with experiments [24] and simulation [29] of self-compression in femtosecond filament. According to the stationary theory (1, 7) signal pulse wavelength λ2 is equal to 8.4 μm (λ1 = 420 nm), 3.6 μm (λ1 = 450 nm) и 2.4 μm (λ1 = 480 nm).…”

“…( 1 ) Duration of compressed femtosecond laser pulses in filament at the fundamental laser frequency is 2 -3 oscillations of the light field [23,24] or 5 -8 fs for the radiation of Ti:Sa laser system (800 nm). Because of the cross focusing phenomenon [15,25] signal and seed pulses propagates together with intense pump pulse, which one is their energy source.…”

Tracing Evolution of Angle-Wavelength Spectrum along the 40-m Postfilament in Corridor Air

“…In opposite, the infrared wing of the spectrum tends to converge towards the axis producing a light bullet [45][46][47]. In the temporal domain the pulse is self-compressed down to ∼10 fs pulse in atmospheric pressure gases and in the collimated beam geometry [48,49].…”

Self-compression of 120 fs pulses in a white-light filament

“…Given that there is little alternative for scaling pulse energies above 10 mJ, however, it is the few-hertz class of lasers that could benefit most from filamentation as there are essentially no working schemes for pulse compression in this regime. For 10 Hz laser systems filament self-compression has been demonstrated [17], however, only for pulse durations smaller than 50 fs. In the following, we will demonstrate filament self-compression with a 10 Hz laser system that neither exhibits exceptional beam quality nor sub-100 fs pulse duration.…”