Spectral signal enhancement in laser-induced breakdown spectroscopy via arc discharge assistance

Abstract

In this study, a technique combining arc discharge with laser-induced breakdown spectroscopy (AD-LIBS) was developed to investigate the influence of arc discharge on the spectral enhancement of Si plasma. The study focused on its effects on spectral intensity, electron density, plasma temperature, and signal-to-noise ratio (SNR) under varying laser energies in both nanosecond (ns) and femtosecond (fs) regimes. The arc discharge device features a simple design, low cost, and minimal safety concerns, making it a promising approach for future development. Experimental results show that AD-LIBS significantly improves spectral intensity and SNR in both ns-LIBS and fs-LIBS modes. In particular, the arc discharge yields a more pronounced SNR enhancement at lower energies in fs-LIBS. With increasing laser energy, both electron density and plasma temperature are higher when arc discharge is applied compared to the conventional LIBS setup, and the plasma temperature in fs-LIBS is slightly higher than that in ns-LIBS. Finally, the morphological characteristics of ablation under nanosecond and femtosecond laser conditions with and without arc discharge were reported. These findings demonstrate that the incorporation of arc discharge can effectively enhance the detection sensitivity of LIBS, offering a new pathway toward high-precision and high-sensitivity spectroscopic analysis.