Investigating the application of adaptive optics in femtosecond filament-assisted remote sensing under atmospheric turbulence

Femtosecond filamentation is a unique phenomenon that allows a pulsed laser beam to suppress diffraction in long-range propagation. In remote sensing of solids, filamentation is used for remote ablation and plasma generation for optical emission spectroscopy. However, in real world conditions, turbulence is known to induce multi-filamentation and pointing instability of the femtosecond laser filament. In this work we combine experiments and simulation to quantify and correct for the effects of turbulence in remote plasma generation. First, we experimentally quantify the effects of turbulence in ablation and corresponding spectral emission of solid samples under varying turbulence strengths. Additionally, we explore strategies for mitigation of turbulence effects, including the use of adaptive optics. We present wavefront measurements from the ablation of target material, which contains optical emission from the plasma and the scattered femtosecond laser itself. Using numerical simulation of femtosecond laser propagation, we show that an adaptive optics system can effectively mitigate turbulence effects, thereby improving the pointing stability and filament onset control.