Role of laser pulse energy as an effective strategy to improve the signal intensity in laser-induced breakdown spectroscopy

Abstract

The effect of laser pulse energy on signal enhancement of aluminium (Al) plasma generated by a nanosecond Nd:YAG laser at various delay times was studied. Plasma evolution has been investigated from emission spectrum by varying energy of laser pulse and time delay. It was determined that the intensity of Al spectral lines decreased with increasing laser delay time. Plasma parameters have been extracted from experimentally recorded line profiles of neutral aluminium. The Boltzmann plot and Stark broadening method were used to evaluate, electron temperature (T_e) and electron density (N_e), respectively. It was found that increasing laser energy causes a rapid increase in electron temperature and electron number density of Al plasma. The optimized conditions yielded T_e = 8488 K and N_e = 1.96 × 10¹⁶ cm⁻³ at 160 mJ and 11 µs delay. The study aims to enhance LIBS detection sensitivity by optimizing laser pulse energy. This work uniquely demonstrates how combined tuning of laser energy and delay time can reduce matrix effects and improve signal intensity, offering a practical route to more sensitive LIBS diagnostics. Such optimization may enhance LIBS applications in real-time industrial alloy analysis and environmental monitoring.