Ultra-short pulsed laser ablation of highly oriented pyrolytic graphite

摘要

Highly oriented pyrolytic graphite (HOPG) targets were irradiated by use of an ultra-short pulsed (pico to femtosecond) Ti:Sapphire laser operating at 825-nm wavelength. The morphology and quality of laser ablated surfaces were characterized by styles profilometry, scanning electronmicroscopy (SEM), atomic force microscopy (AFM), and Raman spectroscopy. The results were also compared with those obtained in nanosecond pulsed excimer laser ablation.The ablation rats expressed in depth per pluse were substantially higher for ultra-short pulsed lasers, and were in close agreement with the theoretical model predictions of laser-solid interactions in the sort-pulse regime. Post-analysis of laser irradiated regions revealed a reduction in thermal effects and a decrease inthe formation of diamond-like carbon as the pulse width was shortened. This work demonstrates the clean and precise machining capabilities of ultra-short pulsed lasers for HOPG that could be applied inthe areas of thin-film deposition, nanotube synthesis, and dust-free machining.