Single-pass cutting of frosted glass via change of laser incident medium

We report a water medium-assisted composite laser cutting (WMACLC) technology for what is believed to be the first time to achieve single-pass separation of frosted glass (FG). The water medium was used to flatten the surface of FG to reduce the diffuse reflection and random refraction of the incident laser. The simulation results of picosecond pulsed laser Bessel beam (PPLBB) intensity distribution in FG showed that the peak intensity in the presence of water can reach about 24 times and 2.3 times that in the absence of water when the PPLBB is 0.08 mm and 0.3 mm below the upper surface of FG, respectively. A PPLBB with higher intensity can be formed along the thickness direction to realize the material modification. A coaxial CW laser provides the thermal tensile stress required for separation. Finally, high-quality separation of FG was achieved using the WMACLC technology with a speed of 50 mm/s. No deviation in the separation track and no edge collapse occurred. The roughness Sa of the separated sidewall is less than 0.3 µm.