Effect of Glass Constraint Width on Axial Stress and Longitudinal Wave Amplitude

Figure Ⅰ presents the findings of the experiment depicted in Figure 9 of the manuscript. It highlights the enhancement achieved by incorporating glass constraints of varying widths at the laser spot, in comparison to a free surface. This enhancement manifests as an increase in the axial stress main pulse amplitude and the transmitted longitudinal wave amplitude.

The results from Figure Ⅰ indicate that the glass constraint intensifies with a broader glass width, leading to a greater axial stress tensor and a larger generated longitudinal wave amplitude. However, beyond a specific threshold glass width (approximately 1.2mm), the gains in axial stress tensor main pulse amplitude and transmitted longitudinal wave amplitude stabilize. This observation implies that beyond a certain level of constraint effect, further expanding the glass width doesn't yield substantial additional gains.