Unusual parallel laser irradiation for suppressing self-absorption in single pulse laser-induced breakdown...

Area of Science:

• Analytical Chemistry
• Spectroscopy
• Laser Physics

Background:

• Self-absorption is a significant challenge in laser-induced breakdown spectroscopy (LIBS), affecting spectral line intensities and quantitative analysis.
• Traditional single-pulse LIBS methods often struggle with self-absorption, especially for high-concentration elements.

Purpose of the Study:

• To develop and demonstrate a novel approach for suppressing the self-absorption effect in single-pulse LIBS.
• To improve the analytical performance and quantitative accuracy of LIBS.

Main Methods:

• Utilized a nanosecond Nd:YAG laser (1064 nm) for parallel laser irradiation, focused 1 mm from the sample surface.
• Generated sample ablation via a shockwave from air breakdown plasma formed near the sample.
• Acquired and analyzed atomic emission spectra in air at atmospheric pressure.

Main Results:

• Successfully obtained spectra of potassium (K I 766.4 nm and K I 769.9 nm) free from self-reversal and with minimal self-absorption.
• Achieved linear calibration curves for potassium over a wide concentration range.
• Demonstrated a significant reduction in the self-absorption effect.

Conclusions:

• The parallel laser irradiation technique effectively suppresses self-absorption in single-pulse LIBS.
• This method enhances the reliability and accuracy of quantitative elemental analysis using LIBS.
• The technique offers improved analytical performance for LIBS applications.