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. To clearly identify the role of aberrations, all the optical elements were taken to have same focal length. The subsequent filament structure and emissions from the filament were correlated with the aberrations induced by optical element revealed stark differences. The onset of the filamentation, its longitudinal intensity and the associated supercontinuum emission (SCE) have varied drastically with the aberrations induced by the focusing optics. A systematic study directed to choose and identify suitable optical elements according to the usage of the fs pulses for a specific filamentation regime is presented. (C) 2021 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

Automated summary

Filamentation of femtosecond laser pulses in atmosphere is influenced by input laser, focusing optics, and medium characteristics. Different optical elements used for focusing the laser pulses can induce aberrations, leading to variations in filament structure and emissions. Systematic study is needed to select suitable optical elements for specific filamentation regimes of femtosecond pulses.