## 3 Results and Discussion  
### The Influence of the Number of Processing Pulses on the Cutting Effect  
The samples were laser cut with 1, 2, 3, 4, and 5 pulse train patterns at a laser frequency of 100 kHz. The test results are shown in Figure 4. The concentration of energy from a single pulse results in incomplete, reforming near the upper and lower surfaces of the sample, where transition ablation can be seen on the upper surface and areas of melt sputtering can be seen after the ablation. The overall correction was observed to be the most uniform and effective when using the dual pulse string mode. This is due to the fact that the first sub-pulse in the pulse string ionizes a large number of free electrons when it reaches the surface of the sample, and the free electrons interact with the lattice to produce a good melting effect; then, when the second sub-pulse is injected, the energy is redistributed, which affects the distribution of the electron density and optimizes the melting effect of the first sub-pulse. As the number of pulse trains increases, it is clear that the unmodified area of the sample also increases, which is attributed to the fact that too many pulse trains dispersed the energy, resulting in incomplete modification of the microcrystalline glass.  
Atomic force microscopy (AFM) morphology was performed on localized areas of the sample cross-section with pulse string modes of 1, 2, 3, 4, and 5, as shown in Figure 5. The local topographic analysis shows that the area of the unmodified region is larger when the pulse pattern is set to 1. In contrast, when the number of pulses was 2, the overall retexturization appeared to be the most uniform and fine. At pulse number 3, due to the decrease in energy contained in each individual pulse, a few localized untextured areas appeared, as evidenced by the increase in the height of the columns with the maximum roughness in the textured area and the appearance of lagging areas. When we further adjusted the pulse pattern to 4, these hysteretic regions expanded more in the unmodified region and the roughness risers were seen to be more concave and inconsistent; however, when the pulse pattern number was 5, the blocky risers began to appear in the unmodified region, when the roughness reached its maximum.  
Figure 3: Bessel beam simulation results. (**a**) Bezier spot pattern; (**b**) Bezier beam intensity distribution.  
When the laser injection power is set at 10 W and the processing point spacing is 1 \(\upmu\)m, the relationship between breaking strength and the number of pulses is illustrated in Figure 6b. As depicted in Figure 6b, when the pulse count reaches 2, the fracture strength of the sample is observed to be at its minimum. However, as the number of pulses continues to increase beyond this point, an enhancement in fracture strength can be noted. The trend regarding stress variation with respect to fracture mode aligns consistently with that of surface roughness. Additionally, modifications made within the correction area significantly influence both the fracture strength and roughness characteristics of the specimen section.  
Figure 4: Sample cross sections with different pulse numbers when the laser incident power is 10 W and the interval is 1 \(\upmu\)m. (**a–e**) are the cross sections of samples when the number of burst modes is 1–5.  
Figure 5: When the distance between the processing points is 1 \(\upmu\)m and the laser incident power is 10 W, the local AFM morphology of the sample section under the number of 1–5 pulse trains is shown as (**a–e**) respectively.  
In summary, when the pulse number is 2, the processing effect is the best.