Direct microwelding and sealing of glass-ceramics with burst-mode ultrafast laser

Glass-ceramics, a type of transparent hard and brittle material with ultra-low thermal expansion coefficients, find extensive applications in aerospace, precision optoelectronics, and other fields. Research on high-efficiency and high-quality welding and sealing technologies for glass-ceramics has become a key focus of current attention. In this work, ultrafast laser micro-welding technology was applied to the direct-write selective welding and sealing of glass-ceramics. Using burst-mode ultrafast lasers, we systematically investigated the effects of pulse duration within bursts, pulse energy, welding speed, and welding line patterns on interfacial material fusion. Furthermore, direct-write sealing of glass–ceramic optical chambers was performed using grid-structured weld lines with burst-mode ultrafast lasers. With the surface flatness of samples being only one wavelength at 632 nm, a sealing leak rate of 10⁻⁷ Pa·m³/s was achieved. These results demonstrate that this technology exhibits significant advantages in the field of high-efficiency, high-quality, and chemical contamination-free welding and sealing of optical chambers.