Fig. 1. Schematic diagram of experimental setup for picosecond laser ablation

Fig. 2. (a) Far-field light spot morphology of picosecond laser beam; (b) scanning scheme of laser ablation cutting

Fig. 3. Measurement results of ablation thresholds on front and rear surfaces of K9 glass

Fig. 4. Ablation morphologies of (a)(b) front and (c)(d) rear surfaces irradiated by single pulse and eight pulses with laser fluence of 13.3 J/cm2

Fig. 5. 2D cross-sectional profiles of ablation craters indicated by red lines in Fig.4

Fig. 6. Variation of ablation depth of K9 glass rear surface with number of laser shots under different laser fluences

Fig. 7. SEM images of K9 glass rear surface after single shot with laser fluence of (a) 4.5 J/cm2 and (b) 37.3 J/cm2, respectively

Fig. 8. Ablation morphology of front surface at laser fluence of 17.3 J/cm2 and scanning speed of 0.03 mm/s. (a) m=1, n=1; (b) m=1, n=2; (c) m=10, n=1; (d) m=10, n=2

Fig. 9. Ablation morphology of rear surface corresponding to those in Fig. 7. (a) m=1,n=1; (b) m=1,n=2; (c) m=10,n=1; (d) m=10,n=2

Fig. 10. Rear surface morphologies after single line and single pass ablation under different laser fluences, scanning speed, and pulse spatial overlap ratios. (a) 11.1 J/cm2, 0.01 mm/s, 90%; (b)13.2 J/cm2, 0.01 mm/s, 90%; (c) 13.2 J/cm2, 0.02 mm/s, 80%

Fig. 11. Ablation quality distribution of rear surface after single line and single pass ablation (m=1, n=1) under different scanning speed and laser fluences