HIGH-SPEED MACHINING OF GLASS MATERIALS BY LASER-INDUCED PLASMA-ASSISTED ABLATION USING A 532-NM LASER

In this communication, we report a high-speed machining of glass mater ials by a novel laser ablation technique using a conventional visible laser for the first time. A high-quality micrograting structure is fab ricated in fused quartz by laser-induced plasma-assisted ablation (LIP AA) using a second harmonic of Q-switched Nd+:YAG laser (532 nm). The plasma generated from a silver (Ag) target by the laser irradiation ef fectively assists in ablation of the fused quartz substrate by the sam e laser beam, although the laser beam is transparent to the substrate. A grating with a cross-sectional shape like a square-wave (period app roximate to 20 mu m) is achieved using the mask projection technique. The ablation rate reaches several tens nm/pulse. In addition, LIPAA is applied to highspeed hole drilling (700 mu m in diameter) of fused-qu artz (0.5 mm thick) and Pyrex glass (0.5 mm thick).