532 nm Nanosecond laser cutting solar float glass: Surface quality evaluation with different laser spot positions in field lens

•Shape of the laser spot in focus changes with the position of the spot.•Relationship between spot offset distance and cutting effect is not linear.•Distribution of burrs on the cutting surface is not random. Influence of laser spot focusing positions in field lens on surface quality was investigated in 532 nm nanosecond laser cutting of solar float glass. Bottom to up cutting method with X–Y helix was selected, and 16 groups of experiments have been designed with different parameters (including cutting speed, frequency, helix width and overlap rate). 6 groups of them with a long distance between field lens center and laser spot focusing position were selected to obtain maximum height values of cutting surface profile. Results indicated that cutting surface qualities are at the same level when offset distance (defined from cutting line to center point of the field lens) is under 20 mm. Conversely, as offset distance was longer than 20 mm, surface quality was in an instable state. The results also showed that white spots on the surface were randomly distributed, while burrs were localized on the side where laser cuts in.