Effect of pulse to pulse interactions on ultra-short pulse laser drilling of steel with repetition rates up to 10 MHz
- 25 July 2014
- journal article
- research article
- Published by Optica Publishing Group in Optics Express
- Vol. 22 (15), 18790-18799
- https://doi.org/10.1364/oe.22.018790
Abstract
We report on the effect of pulse to pulse interactions during percussion drilling of steel using high power ps-laser radiation with repetition rates of up to 10 MHz and high average powers up to 80 W. The ablation rate per pulse is measured as a function of the pulse repetition rate for four fluences ranging from 500 mJ/cm2 up to 1500 mJ/cm2. For every investigated fluence an abrupt increase of the ablation rate per pulse is observed at a distinctive repetition rate. The onset repetition rate for this effect is strongly dependent on the applied pulse fluence. The origin of the increase of the ablation rate is attributed to the emergence of a melt based ablation processes, as Laser Scanning Microscopy (LSM) images show the occurrence of melt ejected material surrounding the drilling holes. A semi empirical model based on classical heat conduction including heat accumulation as well as pulse-particle interactions is applied to enable quantitative conclusions on the origin of the observed data. In agreement with previous studies, the acquired data confirm the relevance of these two effects for the fundamental description of materials processing with ultra-short pulsed laser radiation at high repetition rates and high average power.This publication has 29 references indexed in Scilit:
- In situ imaging of hole shape evolution in ultrashort pulse laser drillingOptics Express, 2010
- Atomistic Modeling of Short Pulse Laser Ablation of Metals: Connections between Melting, Spallation, and Phase ExplosionThe Journal of Physical Chemistry C, 2009
- Time-Resolved Shadowgraphs of Material Ejection in Intense Femtosecond Laser Ablation of AluminumPhysical Review Letters, 2007
- Time Resolved Shadowgraph Images of Silicon during Laser Ablation: Shockwaves and Particle GenerationJournal of Physics: Conference Series, 2007
- Pulse width and energy influence on laser micromachining of metals in a range of 100fs to 5psApplied Surface Science, 2005
- Metallographical analysis of steel and hard metal substrates after deep-drilling with femtosecond laser pulsesApplied Surface Science, 2003
- Shock wave and material vapour plume propagation during excimer laser ablation of aluminium samplesJournal of Physics D: Applied Physics, 1999
- Ablation of metals by ultrashort laser pulsesJournal of the Optical Society of America B, 1997
- Short-pulse laser ablation of solid targetsOptics Communications, 1996
- Femtosecond, picosecond and nanosecond laser ablation of solidsApplied Physics A, 1996