Spectral intensity clamping in linearly and circularly polarized femtosecond filament-induced Cu plasmas

Abstract

It is well known that the properties of femtosecond laser filamentation strongly depend on laser polarization. The spectral emission generated by linearly polarized femtosecond filament-induced breakdown spectroscopy will differ from that in the circularly polarized femtosecond one. This study investigated the emission features of plasmas generated by using a circularly or linearly polarized femtosecond laser filament from a Cu target. The differences between the lengths of the clamped spectral intensity zones along the filament were obtained by using optical emission spectroscopy. The spectral intensity along the filament propagation path in the circular polarization case was more stable against small perturbations compared with that in the linear polarization one.