Femtosecond Laser Filamentation in Atmospheric Turbulence

TL;DR

This study experimentally investigates how atmospheric turbulence affects femtosecond laser filamentation, revealing that increased turbulence alters filament start position, length, and stability, with implications for laser propagation in complex environments.

Contribution

It provides new experimental insights into the effects of atmospheric turbulence on femtosecond laser filaments, including filament behavior and displacement under varying turbulence conditions.

Findings

Increased turbulence intensity raises filament start position.

Turbulence expansion shortens filament length.

Filament displacement standard deviation relates to turbulence parameters.

Abstract

The effects of turbulence intensity and turbulence region on the distribution of femtosecond laser filaments are experimentally elaborated. Through the ultrasonic signals emitted by the filaments, and it is observed that increasing turbulence intensity and expanding turbulence active region cause an increase in the start position of the filament, and a decrease in filament length, which can be well explained by the theoretical calculation. It is also observed that the random perturbation of the air refractive index caused by atmospheric turbulence expanded the spot size of the filament. Additionally, when turbulence intensity reaches , multiple filaments are formed. Furthermore, the standard deviation of the transverse displacement of filament is found to be proportional to the square root of turbulent structure constant under the experimental turbulence parameters in this paper. These results contribute to the study of femtosecond laser propagation mechanisms in complex atmospheric turbulence conditions