Difference in filament and spectrum broadening induced by femtosecond pulses in argon gas with a temperature gradient at different positions

By increasing the local temperature at different positions along the argon gas-filled tube, the difference in filament and spectrum broadening was compared in this paper. The experimental results show that the filament can be controlled by increasing the local temperature of the gas-filled tube. The best way to realise the maximum of such a influence is to heat at the focus point. Spectrum broadening will be narrow with the increase of the local temperature.