Glass cutting remains one of the most common glass processing steps, and the demand for fast and high-quality glass cutting has increased significantly over recent years. For such a task, modern ultrashort lasers with high average power and high pulse repetition rate have become a promising tool. The most well-established laser-based cutting techniques are direct laser ablation, ablation from the bottom side (bottom-up technique), and crack generation in the bulk of the glass. However, the bottom-up technique generates large cut edge chipping, while the crack generation approach has cutting geometry limitations, making direct laser ablation the most promising technique. Furthermore, multiple studies have shown that direct laser ablation efficiency and processing quality can be significantly improved in a water-assisted environment. In the previous work, we confirmed higher ablation efficiency and improved cutting quality in a water-assisted environment with 1064 nm wavelength laser radiation. However, transition to shorter wavelengths should further improve the cut quality and decrease ablation threshold due to a better laser energy coupling in glass and lower laser light absorption in the liquid layer.

    Thus, a picosecond laser working at 355 nm wavelength was used to cut 400 µm thick borosilicate glasses in ambient air and water-assisted environments. Ablation efficiency, together with cutting quality (edge chipping, surface roughness, and flexural strength), were evaluated. Laser processing parameters were separately optimized for each cutting environment to maximize the ablation efficiency. Furthermore, we found that the hatch distance had a significant influence on the cut wall quality and the ablation efficiency, but the effect on the bending strength of laser-cut glass parts was minor. Water-assisted ablation was more effective than ablation in ambient air, average edge chipping was 7.5 times lower in water-assisted conditions, the maximum size of chips was similar in both cutting environments, and surface roughness was 1.75 times lower when glass was cut in ambient air.