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• Laser patterning of thin films on flexible substrates. • Observation and analysis of patterning-induced surface effects. • Insight into rapid nanosecond ablation properties in thin film materials. • Demonstration of ultra-fast scanning utilization on in-demand electronic materials. Modern electronics facilitate the need for fast, efficient, and reliable methods for direct laser-based surface engineering of conductive thin film materials on flexible substrates. Recent advances in pulsed laser source development only incrementally increased the processing speeds, as those are limited by the available scanning systems. Our goal was to combine a high pulse repetition frequency high-power pulse-on-demand fiber laser source with an ultra-fast resonant scanner to achieve high throughput surface engineering. The enabling factor to compensate a resonant scanner's sinusoidal movement were the laser's intrinsic pulse-on-demand capabilities beyond simple pulse picking solutions. The high temporal resolution at full laser power was exploited for spatially controlled surface texturing, allowing a minimally 3 μm positioning accuracy throughout the scanner's range at up to 60 m/s scan speed with a 10 μm laser spot size. We applied the setup to processing of ITO and metallic films on flexible substrates for touchscreens, position sensors, or EM shielding. Surface modification and patterning of the conductive layer was successfully demonstrated while keeping the underlying surface intact. We employed a simple laser ablation model in comparison to the experimental data to improve the understanding of the ablation process. The resulting surface topography was observed and analysed. [ABSTRACT FROM AUTHOR]

• Visualization of the growth of cavitation bubbles near the nucleation energy threshold. • Report on low and high conversion of excitation energy to the cavitation. • Visualization supported shockwave pressure measurement and modeling. • Laser induced cavitation bubbles of few μm diameter generated by 60 ps 515 nm laser. The nucleation and growth of cavitation bubbles few micrometers in size in water generated by a 60 ps 515 nm fiber laser is observed and visualized near nucleation threshold. The study is performed by monitoring the plasma size, the cavitation bubble size and the emitted shock waves. The latter two aspects are supported by the Gilmore model using a Noble-Abel-stiffened-gas (NASG) equations of state. For the first time, two types of cavitation events are identified and visualized that exhibit a difference of more than two orders of magnitude in the excitation energy converted to mechanical effects with minimal change in excitation laser pulse energy. The result is localized cavitation and reduced mechanical stress on water-based media with potentially positive implications for laser treatments of biological tissue. [ABSTRACT FROM AUTHOR]