Intense laser filament-solid interactions from near-ultraviolet to mid-infrared

Area of Science:

• Laser-Matter Interaction
• Remote Sensing Technologies
• Plasma Physics

Background:

• High-power ultrashort laser pulse interactions with matter are crucial for fundamental science and remote sensing.
• Understanding laser filament coupling to solid targets is key for optimizing material analysis techniques.

Purpose of the Study:

• To investigate the influence of laser wavelength on the coupling efficiency of femtosecond laser filaments to solid targets.
• To elucidate the mechanisms behind wavelength-dependent ablation and plasma dynamics in laser-matter interactions.

Main Methods:

• Utilized femtosecond laser filaments at three central wavelengths: 0.4 µm, 0.8 µm, and 2.0 µm.
• Analyzed filament-induced plasma dynamics and thermodynamic parameters.
• Compared ablation efficiency across different wavelengths, contrasting with conventional tight focusing.

Main Results:

• Shorter laser wavelengths (e.g., near-UV) did not consistently yield more efficient material ablation.
• Increased multi-photon absorption was identified as a key factor limiting ablation efficiency at shorter wavelengths.
• Detailed plasma dynamics and thermodynamic parameters were characterized for different wavelengths.

Conclusions:

• The relationship between laser wavelength and ablation efficiency is complex, influenced by nonlinear absorption processes.
• Findings provide a foundation for understanding wavelength-dependent ablation mechanisms in laser-matter interactions.
• Improved understanding can enhance strategies for material detection sensitivity and analytical performance in remote sensing.