Fig. 1. Schematic of setup for glass processed by 248 nm excimer laser

Fig. 2. Main experimental setups. (a) Excimer laser; (b) processing platform

Fig. 3. (a)-(d) Optical microscope photographs of silicon glass etched under different laser energy densities; (e) laser etching rate for silica glass versus laser energy density

Fig. 4. Changing trends of bottom morphology of statically etched micro-groove in X and Y directions

Fig. 5. Optical microscope photographs of etched silica glass. (a) Morphology of sediment surrounding statically etched groove; (b) morphology of sediment of direct-writing etched micro-groove

Fig. 6. Local SEM photos for sediment of etched silica glass. (a) Scattered particles; (b) fused attachments

Fig. 7. Bottom morphologies of micro-grooves under different numbers of laser pulses. (a) 20 pulses; (b) 40 pulses; (c) 80 pulses; (d) 120 pulses

Fig. 8. Crack conditions of silica glass surface with defect. (a) Original surface; (b) crack condition 1 after etching; (c) crack condition 2 after etching

Fig. 9. Morphologies of silicon glass micro-grooves under different laser repetition frequencies. (a) 6 Hz; (b) 10 Hz; (c) 20 Hz; (d) 50 Hz

Fig. 10. (a)-(c) Optical microscope photos of micro-grooves under different scanning times at repetition frequency of 20 Hz; (d) micro-groove depth versus scanning times

Fig. 11. Optical microscope photos of circular micro-grooves when scanning times is (a) 1 and (b) 2 at repetition frequency of 50 Hz; (c) optical microscope photo of circular micro-groove when scanning times is 3 at repetition frequency of 30 Hz

Fig. 12. Optical microscope photos of crack-free silica glass micro-grooves when laser energy density is 23.5 J·cm-2 and scanning speed is 6 mm·min-1. (a) Overall structure; (b) circular arc section (laser repetition frequency is 50 Hz); (c) straight line section (laser repetition frequency is 40 Hz)