Spatio-temporal analysis of glass volume processing using ultrashort laser pulses

Area of Science:

• Materials Science
• Laser Physics
• Non-linear Optics

Background:

• Ultrashort laser pulses enable in-volume glass processing via non-linear absorption.
• Understanding laser-matter interactions is crucial for optimizing this technology.
• Energy deposition and relaxation dynamics are key to material modification.

Purpose of the Study:

• Investigate the spatio-temporal evolution of free carriers and energy transfer in glass during and after ultrashort laser pulse exposure.
• Analyze the resulting permanent modifications within the glass volume.
• Correlate transient distributions with refractive index changes.

Main Methods:

• Utilized time-resolved microscopy to capture shadowgraphic and interferometric images.
• Examined the effects of femtosecond and picosecond laser pulses.
• Analyzed the influence of pulse duration, pulse energy, and focus geometry.

Main Results:

• Observed plasma generation time dependent on pulse duration.
• Identified thermal dynamics occurring over microseconds.
• Documented the emergence of a pressure wave due to rapid temperature and pressure increases.
• Demonstrated that modification structures, including disruptions and defects, are controllable.

Conclusions:

• The study provides insights into the fundamental processes governing laser-induced modifications in glass.
• Results show that careful selection of laser parameters can precisely control the resulting material structure.
• This understanding is vital for advancing applications in precision glass manufacturing and modification.