Enhancing elemental visualization imaging accuracy on irregular material surfaces with an auto-focus laser-induced
Shangyong Zhao1, Jingyi Wu2, Zhangrong Li2
1Zhejiang A&F University, College of Optical, Mechanical and Electrical Engineering, Hangzhou, 311300, PR China; Tsinghua University, State Key Laboratory of Power System Operation and Control, Department of Electrical Engineering, Beijing, 100084, PR China.
Talanta
|April 12, 2026
Summary
This study introduces auto-focus LIBS (AF-LIBS) imaging to overcome signal loss on irregular surfaces. The new method dynamically adjusts focus, significantly improving elemental analysis accuracy for complex materials.
Area of Science:
- Analytical Chemistry
- Spectroscopy
- Materials Science
Background:
- Laser-induced breakdown spectroscopy (LIBS) is crucial for elemental surface analysis.
- Conventional LIBS struggles with irregular surfaces due to defocus, causing signal attenuation and reduced accuracy.
- Existing solutions like precision platforms and algorithms have limitations in efficiency and signal-to-noise ratio.
Purpose of the Study:
- To develop a novel auto-focus LIBS (AF-LIBS) imaging method for accurate elemental analysis of irregular surfaces.
- To address the defocus problem inherent in traditional LIBS imaging.
- To enhance the stability and precision of elemental distribution mapping.
Main Methods:
- Integration of a motor-driven focusing mirror module for dynamic focal adjustment.
- Real-time tracking of surface height variations to maintain stable plasma excitation.
- Application of a zoning strategy for data analysis on complex surfaces.
Main Results:
- AF-LIBS significantly reduced the relative standard deviation (RSD) of spectral line intensities to below 9.65% on surfaces with ~26 mm height variations.
- The AF-LIBS method improved spectral signal intensity stability by a factor of 8.12 compared to static ns-LIBS.
- Demonstrated fundamental resolution of the defocus issue in LIBS imaging for irregular samples.
Conclusions:
- The proposed AF-LIBS method fundamentally overcomes the defocus limitation for LIBS imaging on irregular surfaces.
- This technology enhances analytical precision and provides more reliable elemental distribution images.
- AF-LIBS expands LIBS applications to complex materials in fields like biomedicine, archaeology, and materials science, facilitating field-based analysis.
