飞秒激光作用下全向高反膜破坏的激发过程

设计和制备了全向高反膜SiO2／TiO2，研究了它在不同脉冲宽度、不同脉冲能量的飞秒激光作用下的破坏阈值和烧蚀深度．利用发展的抽运．探针方法，研究了抽运脉冲作用下材料中导带电子的超快激发和能量沉积过程，建立并求解了飞秒激光激发材料和材料的激发对抽运光自身反作用的耦合动力学模型．模型较好地揭示了材料破坏的激发过程．

The onmidirectional reflector SiO2/TiO2 is prepared and its threshold fluences and ablation depths at different pulse durations and fluences is studied. In addition a new pump and probe experiment system is developed. The probe pulse is kept as short as possible, while, the pump pulse is stretched and its duration is much longer than that of the probe pulse. Time-resolved excitation processes and damage mechanisms in onmidirectional reflector SiO2/TiO2 is studied. A coupled dynamic model, not only considering the excitation of the material by the laser, but also the counteraction of this excitation to the laser, is employed to study the damage mechanisms. This model well explains the excitation processes during the damage of omnidirectional reflector.