Filament-induced breakdown spectroscopy of solids through highly scattering media

Area of Science:

• Optics and Photonics
• Atmospheric Science
• Spectroscopy

Background:

• Ultrafast laser pulse filamentation in air is a key technique for remote sensing via filamentation-induced breakdown spectroscopy.
• Scattering in environments like fog, haze, and clouds impedes laser propagation and optical signature retrieval.

Purpose of the Study:

• To demonstrate laser filamentation's capability to clear paths in scattering media.
• To show simultaneous plasma generation and spectroscopic signal detection along the cleared path.

Main Methods:

• Utilizing intense femtosecond laser pulses to induce filamentation in a highly scattering medium (dense cloud).
• Generating luminous plasma on a solid target.
• Analyzing the counter-propagation of spectroscopic signals through the cleared filament channel.

Main Results:

• Laser filamentation effectively cleared a path for pulse propagation in a dense cloud.
• A spectroscopic signal was successfully counter-propagated along the cleared channel.
• The signal's transit was primarily on-axis but influenced by negative thermal lensing.

Conclusions:

• Laser filamentation offers a viable method for remote sensing in poor visibility conditions.
• Understanding thermal lensing effects is crucial for optimizing signal retrieval.
• This research significantly enhances capabilities for atmospheric sensing and remote detection.