The instability of laser-induced plasma fronts in fused silica under coupled magnetic-field and dual-pulse laser irradiation remains insufficiently quantified, particularly in terms of the link between front morphology, plasma-state parameters, and multiscale transport anisotropy. Here, we investigate the evolution of magnetically modulated plasma-coupled thermo-pressure wave fronts generated by a combined millisecond–nanosecond laser system. Time-integrated plasma images, acoustic emission, and optical emission spectra are used to characterize the front dynamics, damage response, and plasma state. Image-statistics analysis reveals pronounced edge splashing, boundary corrugation, broadened pixel-intensity distributions, and a long, high-relative standard deviation tail, providing direct experimental evidence of front instability and spatial nonuniformity. Increasing magnetic-field strength enhances electron temperature, electron density, and spectral intensity, while a pulse delay of 1.0 ms yields the strongest plasma response at 0.6 T, indicating optimal temporal matching between millisecond preheating and nanosecond energy injection. The results show that magnetic confinement suppresses transverse transport, promotes local energy accumulation, and amplifies front distortion, splitting, and collapse. These findings establish a framework for understanding magnetically modulated plasma instability and fused-silica damage under combined-laser irradiation.
Liu et al. (2026) studied this question.