Laser ablation ignition of premixed methane and oxygen-enriched air mixtures using a tantalum target

We report the laser ablation ignition of premixed methane and oxygen-enriched air mixtures using a tantalum target. The minimum laser pulse energy (MPE) of the ablation ignition was obtained as 2-4 mJ, which was reduced by one order of magnitude compared with that of the direct laser-induced gas breakdown ignition. The ignition time of the ablation ignition was investigated for the first time, to our best knowledge, by measuring the emission signal profiles due to the successfully ignited flames, and an ignition time as short as ~50 μs was obtained. The reduction in MPE will promote the miniaturization and, thus, the practical applications of laser ignition systems.