Optics and Photonics Society of Iran

Balance between optical Kerr and plasma defocusing effects causes the femtosecond laser filamentation. In this case the laser intensity inside the laser filament is stable and becomes unvaried during increasing the laser energy. This phenomenon is called intensity clamping. In this paper the super continuum spectrums of the femtosecond Ti: Sapphire laser pulses which were propagated in water, at different input laser energy from 66 µJ to 0.6 mJ were investigated. The experimental results show asymmetric broadening spectrums by increasing the input laser energy .Also it was shown that the blue shifting toward the shorter wavelength is constant for the input energy above 460 µj.