Quantitative analysis improvement of laser-induced breakdown spectroscopy based a newly beam shaping method

Area of Science:

• Spectroscopy
• Laser Physics
• Materials Science

Background:

• Laser-induced breakdown spectroscopy (LIBS) faces challenges in commercialization due to signal uncertainty and low sensitivity.
• Matrix effects, self-absorption, and environmental factors contribute to LIBS signal variability.
• Existing beam shaping optics like diffractive optical elements (DOEs) are expensive and limited to specific laser parameters.

Purpose of the Study:

• To develop a simple, low-cost beam shaping method to enhance LIBS quantitative analysis performance.
• To improve ablation efficiency and reduce plasma shielding effects for stronger, more stable LIBS signals.
• To investigate the impact of an approximately flat-top beam (AFTB) on LIBS signal intensity and uncertainty.

Main Methods:

• Designed a novel beam shaper using plano-concave and plano-convex cylindrical lenses.
• Transformed a Gaussian beam (GB) into an approximately flat-top beam (AFTB) with homogeneous energy distribution.
• Applied the AFTB to LIBS analysis of steel alloy samples.

Main Results:

• Determination coefficients (R²) for trace elements in steel alloy samples improved above 0.9658.
• Root-mean-square-error (RMSE) and average relative error (ARE) were significantly reduced, by up to half and five times, respectively.
• Limits of detection (LOD) with AFTB were slightly lower than with GB.

Conclusions:

• The proposed cylindrical lens beam shaping method effectively enhances LIBS quantitative analysis.
• This low-cost approach offers a practical solution to improve LIBS signal intensity and reduce uncertainty.
• The developed beam shaper shows significant potential for advancing LIBS commercialization and analytical capabilities.