Effect of focusing element-induced aberrations on filamentation and supercontinuum emission in ambient air.

Femtosecond laser pulse induced filamentation in atmosphere is susceptible to a number of input laser, focusing optics and medium characteristics. Filamentation of fs pulses in atmosphere is an intense propagation regime where the focusing geometry used to focus the fs laser pulses play an important role influencing the filament intensity and the associated supercontinuum. We identified different optical elements used for focusing the fs laser pulses leading to filamentation in air and classified them according to the induced aberrations.

Spatio-temporal characterization of ablative Cu plasma produced by femtosecond filaments.

We present the spatial and temporal characterization of the copper (Cu) plasma produced by the femtosecond laser filaments. The filaments of various lengths and intensities were generated with the aid of three different focusing lenses. Further, the filamentation induced breakdown spectroscopy (FIBS) measurements were carried out for each filament at three different positions along the length of the filament.

Supercontinuum generation from zinc borate glasses: bandgap versus rare-earth doping.

We report an enhanced supercontinuum generation (SCG) from a rare-earth () doped low bandgap zinc borate glass when excited with 60 fs pulses from a Ti-sapphire laser. The emission associated with the absorption bands due to doping (around 420-500 and 580-600 nm) is observed to assist the enhanced SCG.