Filamentation of femtosecond radiation from a Cr:forsterite laser in air

The filamentation of radiation from a 1.24-μm femtosecond Cr:forsterite laser in air is studied experimentally and theoretically. The decrease in the laser beam diameter during filamentation was observed. The parameters of filaments produced by radiation from a Cr:forsterite and a Ti:sapphire lasers are compared. It is shown that a filament produced by radiation from the Cr:forsterite laser appears at a larger distance and contains more energy than a filament produced by radiation from the Ti:sapphire laser with the same initial parameters of pulses.