Effect of beam ellipticity on femtosecond laser multi-filamentation regulated by π-phase plate

Abstract

The regulation of multiple filaments during an intense femtosecond laser propagation in a transparent optical medium is still challenging. In this study, by tracing the phase variation of the laser pulse during the propagation, the effect of the beam ellipticity on the generation of multiple filaments was investigated using the efficient π-phase plate. The spatial distribution of the generated multiple filaments did not follow the predesigned pattern of the phase plate when the laser beam was elliptic owing to the asymmetric change of the laser phase by the linear diffraction and nonlinear Kerr effect.

飞秒激光诱导多丝产生与调控研究进展

“…2 Evolution of femtosecond laser propagation in air and gaseous lattice media structures [69] . (a) Three 3 Experimental setup for capturing filament profiles by a digital camera [78] (photos have to be taken in two directions due to asymmetric focusing geometry, i. e. horizontal and vertical direction, which are labeled as x and y, respectively) 4 Focal distribution of nonlinear propagation with different ellipticities and powers [81] (intensity unit: W/cm 2 )…”

Filamentation‐Induced Volume Plasma Grating: Dynamics, Possibilities, and Advantages

“…[14] If it is achiev-able, perhaps we are able to make use of multiple filamentation generation, other than deliberately avoid it. Besides, although studies of planar plasma grating [23][24][25][26] and other techniques to control multiple filaments [27][28][29][30][31][32] might offer us a basic tool for laser modification/ablation, the dimensions of plasma grating are still expected to be increased for further improvements of cross-scale manufacturing.…”