Thermal cleavage on glass by a laser-induced plume

Abstract

We developed a thermal cleaving process on glass using an infrared–laser-induced plume. A pulsed ytterbium fiber laser with a wavelength of 1070nm and a laser pulse energy of 40µJ was used to produce a plasma plume on a carbon-coated sacrificial glass substrate. The induced plasma plume affected the surface of the target glass substrate and changed its optical properties locally. The laser beam that was subsequently absorbed in the modified zone induced localized heating, which led to micro-crack initiation for the glass cleaving. Various processing parameters, such as the laser's power and pulse width, and the distance between the coating layer and the target glass substrate were investigated to optimize the quality of the glass cleave. The quality of the cutting edges and cross sections with respect to these parameters were examined. Numerical simulations of the micro-crack initiation due to heat accumulation were performed to investigate the fracture mechanism and to estimate the expected glass-cleaving line. The limits and applications of the process are also discussed.