| Abstract [eng] |
The dissertation aims to investigate methods for increasing the rate and quality of direct laser glass ablation for fabricating optical elements. The research covered three stages: glass cutting, surface shaping, and polishing. Borosilicate glass substrates (110–550 µm thick) were used in cutting experiments, while 6.3 mm thick fused silica was employed for shaping and polishing. The influence of process parameters (channel width, substrate thickness, fluence, pulse overlap) on cutting speed in air and water was investigated using a femtosecond laser, focusing on complete substrate separation. Process quality was evaluated by measuring edge chipping, sidewall roughness Ra, and the effect on the glass flexural strength. In surface shaping, the influence of laser pulse duration on structuring resolution and surface quality was analyzed by evaluating removed layer thickness and formed surface roughness Sa. Compared with longer picosecond pulses, femtosecond pulses demonstrated superior processing speed, surface quality, and resolution. To further increase the processing rate, the influence of GHz femtosecond pulse bursts was investigated. Finally, the fabrication of lens arrays and polishing using a CO2 laser were demonstrated. The optical elements were tested in an optical system to evaluate their laser beam focusing performance. |
