The mechanism of ablation of sapphire by an ultra-short pulse laser
超短脉冲激光照射下氧化铝的烧蚀机理

Based on the linear dependence of laser pulse energy on the ablation area, the ablation threshold fluence of sapphire is calculated in this paper. Meanwhile the threshold fluence of sapphire as a function of pulse duration is studied with an ultra-short pulse laser. The experimental results agree well with the theory of avalanche mode. Finally we discussed the photon absorption mechanism of the conduction band electrons in Al 2O 3.