Ultrastable Bonding of glass with femtosecond laser bursts

摘要

We report on the welding of fused silica with bursts of ultrashort laser pulses. The bursts consist of ultrashort laser pulses with a repetition rate of 9.4 MHz. However, the time between the laser bursts is about 10 μs, which reduces the maximal temperature rise. Micrographs and simulations show that the molten structures are enlarged while using laser bursts. In addition, the usage of bursts instead of continuous pulse trains reduces the laser induced stress. By optimizing the burst frequency and repetition rate we were able to achieve a breaking resistance of up to 96% of the bulk material, which is significantly higher than in conventional high repetition rate laser bonding.