Theoretical Investigation of Temperature-Gradient Induced Glass Cutting

In this work, it has been shown that during the irradiation of glass by one moving laser beam, an initiation of crack can take place before and behind the irradiation spot. The initiation of a crack before the irradiation spot (within the frontal zone) is implemented at a higher power of laser radiation (or at a lower speed of the movement of the irradiation spot) than the crack initiation behind the irradiation spot (within the rear zone). If the crack is initiated within the frontal zone, the movement of the crack is unstable. The pattern of the movement of the crack depends on random factors such as residual stresses and defects. When the crack is initiated within the rear zone, the movement of the crack is steady because the region near the tip of the crack is surrounded by compressive stresses obstructing its traverse propagation.