Investigation on Laser Material Processing of Glass by Simultaneous Short and Ultrashort Pulses

Processing heat-sensitive materials like glass requires minimizing thermal damage, a challenge for conventional nanosecond lasers.While ultrashort pulsed lasers offer precision, their efficiency can be limited.This study presents method to enhance glass processing by using a mixed-pulse-train (MPT) of synchronized picosecond (ps) and nanosecond (ns) pulses.We demonstrate that this simultaneous approach significantly improves ablation efficiency on soda-lime glass by determining the influence of the nanosecond pulse on the ablation threshold.The ablation threshold was reduced from 3.38 J/cm 2 with ps-only pulses to 2.79 J/cm 2 in MPT mode.This enhancement is critically dependent on the temporal delay, with the lowest threshold achieved when the ns pulse trails the ps pulse by 5 ns.This indicates a synergistic effect where the ps pulse pre-excites the material, increasing the absorption of the following ns pulse.Furthermore, MPT processing resulted in distinct topographical changes, including a wider modification zone and surface elevations up to 40 nm, suggesting localized volume expansion.These findings show that synchronized ps-ns pulses provide a highly controllable method for tailoring material interactions, offering a promising alternative to more complex and costly burst-mode systems for high-precision applications.