Ultra Short Pulse Laser Welding of Glass to Metal in the Low Fluence Regime

ABSTRACT Ultra short pulse laser welding is a promising approach for joining dissimilar materials such as glass and metal with high precision and minimal thermal damage degradation. In this study, we introduce the Two‐Thresholds Criteria to identify optimal laser parameters for successful glass to metal welding. We consider both the intensity threshold for nonlinear absorption in glass and the fluence threshold for metal surface modification. We identify a low fluence regime with respect to the modification threshold at the metal surface, avoiding weld seams with parasitic modifications in the glass or on the metal surface. The Two‐Thresholds Criteria, demonstrated for Borofloat 33 to copper, aluminum, and stainless steel welding, provides a guideline for selecting laser parameters to achieve robust welds for other material combinations.