Direct fabrication of microgratings in fused quartz by laser-induced plasma-assisted ablation with a KrF excimer laser

We report precision microfabrication of fused quartz by laser ablation with a conventional UV laser for what is believed to be the first time. A high-quality micrograting structure is fabricated in fused quartz by a novel technique of laser-induced plasma-assisted ablation with a single KrF excimer laser (248 nm). The plasma generated from a metal target by laser irradiation effectively assists in ablation of the fused-quartz substrate by the same laser beam, although the laser beam is transparent to the substrate. A grating with a period of 1.06 mum is achieved by use of a phase mask. We can control the grating depth to 300 nm by changing the pulse number. This technique permits high-quality microfabrication of electronic and optoelectronic devices based on fused quartz and related silicate materials by use of a conventional UV laser.