Ultrashort pulsed laser welding of crystalline quartz to metals with differing thermo-mechanical properties

We report ultrashort pulse (USP) laser welding of crystalline quartz to four industrial materials: titanium, stainless steel, aluminum, and copper, exhibiting coefficients of thermal expansion (CTE) mismatch from 1.5 to 15.9 μmm^-1K^-1. Welding was conducted using 5 ps, 1030 nm pulses with a high NA focus. Performance was evaluated using stress-induced birefringence, thermal cycling, and shear strength. All samples showed acceptable results with birefringent phase retardation (<5 nm/cm) and breaking strengths varying between 147 ± 60 N for copper and 110 ± 70 N for titanium. Performance variations are attributed to differences in thermo-mechanical properties, with the unexpected observation that it is not dominated by the CTE mismatch.