Objective This study aims to develop a cost-effective and efficient wavelength drift correction method for LIBS systems to address the critical issue of spectral drift caused by temperature variations. The specific objectives include: 1) establishing a rapid and accurate drift detection algorithm based on phase correlation method that avoids the complexity of traditional peak matching approaches; 2) achieving sub-pixel precision correction accuracy comparable to advanced space-based LIBS systems while significantly reducing system complexity and cost; 3) validating the method's effectiveness across different spectral channels and temperature conditions; and 4) providing a practical solution suitable for industrial and commercial LIBS applications.

Methods The phase correlation method was implemented based on the shift theorem of Fourier transform. The algorithm consists of three core stages: signal preprocessing, frequency domain correlation analysis, and precision optimization. In the preprocessing stage, zero-mean normalization and Hanning window functions were applied to improve robustness. The frequency domain analysis utilized Fast Fourier Transform (FFT) to convert spectral signals and calculate normalized cross-power spectrum between reference and test spectra. Sub-pixel precision was achieved through parabolic interpolation of the phase correlation function peak. Experiments were conducted using a 4-channel fiber-optic spectrometer (190-840 nm) and granite standard material GBW07103 at three temperature conditions (20 ℃, 26 ℃, and 34 ℃). The Nd:YAG laser operated at 1064 nm with 50 mJ energy and 10 Hz repetition rate. Twenty spectral acquisitions were averaged at each temperature to reduce random errors.

Results and Discussions The experimental results demonstrate excellent performance of the phase correlation method across all spectral channels. Within the drift range of 0.18-1.53 nm, correction errors were consistently maintained below 0.01 nm, with an average correction error of 0.0034 nm. The method showed stable performance across different temperature conditions and spectral line densities. Channel 4 (610-840 nm) exhibited the largest drift magnitude, while all channels maintained comparable correction accuracy. Comparison with the MarSCoDe LIBS system revealed that while maintaining equivalent correction precision, the proposed method offers significant advantages in computational efficiency (millisecond-level processing), implementation cost (no requirement for feature peak databases or temperature compensation systems), and maintenance simplicity (high automation with minimal parameter adjustment). The method demonstrated superior cost-effectiveness and practical applicability for industrial applications, particularly suitable for portable LIBS devices and online quality control systems.

Conclusions This study successfully developed a phase correlation-based wavelength drift correction method that addresses the critical wavelength drift problem in LIBS technology. The method achieves sub-pixel precision correction (average error: 0.0034 nm) while offering significant advantages in computational efficiency, cost-effectiveness, and practical applicability compared to complex multi-algorithm systems. The core advantages include: 1) extremely high computational efficiency with millisecond-level processing capability suitable for real-time industrial applications; 2) low implementation cost without requiring feature peak databases, temperature compensation systems, or specific standard samples; 3) simple maintenance with high automation and minimal operational complexity; and 4) broad applicability across different sample types and spectral characteristics. This research provides an economical and practical solution for the commercialization and industrialization of LIBS technology, facilitating its widespread adoption in cost-sensitive commercial applications and contributing to the popularization of LIBS technology in small and medium enterprises and emerging application fields.