Effect of laser scanning frequency on the optical transmittance of the welded area in glass laser welding

When conventionally laser-welding transparent materials such as glass, researchers often primarily focus on the material’s joint strength, paying scant attention to variations in optical transmittance within the welding zone. However, in fields like biomedical applications, optical characteristics are also pivotal in characterizing the efficacy of welding. Therefore, this study investigated the relationship between scanning frequency and optical transmittance during laser welding. The findings indicate that a laser single pulse energy of 14.73 μJ, a repetition frequency of 500 kHz, a scanning speed of 600 mm/s, and an optimal scanning frequency of 45 times yielded the highest optical transmittance in the welding area. This resulted in a 13% increase in transmittance compared to stacking two glass pieces.