Abstract
Fusion welding is well known as the most promising technique in glass joining, since joining can be accomplished without any intermediate layer and mechanical contact. High precision, small heat-affected zone (HAZ) and small shock-affected zone (SAZ) by ultra-short pulsed laser make it possible to perform the joining process with minimal damages to the surrounding area. However, there still remained a lot of things to be clarified in this process, since glass materials are very sensitive to temperature gradients. In this study, molten zones created by ultra-short pulsed laser in a fused silica glass were experimentally investigated. Laser irradiation was carried out inside the glass under various processing conditions. Molten zone was observed visually, and its mechanical strength was measured using three points bending test. The strength of molten zone was almost equal to the base material, and high strength could be obtained at low velocity and high pulse repetition rate condition.
