A sudden increase in crater depth was observed during high irradiance (> 10 10 W/cm 2 ) laser ablation of silicon, and it is attributed to the phenomena of phase explosion.The threshold irradiance for phase explosion showed a dependence on two laser parameters; laser beam spot size and wavelength. For a larger beam size and longer incident wavelength, a higher laser irradiance was required to generate phase explosion.The rapid increase of crater depth above the phase explosion threshold irradiance correlated with a significant increase in the ICP-MS signal intensity. The ratio of crater volume to ICP-MS intensity, which represents entrainment efficiency, remained the lowest at laser irradiances slightly above the phase explosion threshold. However, this ratio increased at irradiances well above the threshold (> 10 11 W/cm 2 ). Chemical analysis using laser ablation at irradiance above 10 11 W/cm 2 provides increased sensitivity via improved entrainment and transport efficiency and increased ablation rate.