多脉冲激光作用下光学薄膜损伤的累积效应

研究了高反射膜在多脉冲激光作用下损伤的累积效应.实验中使用1064nm调Q的Nd∶YAG激光器，脉宽是12 ns，频率为10 Hz.实验发现:高反射膜的损伤阈值随辐照脉冲数增加而降低，表现出明显的累积效应.通过对损伤阈值和损伤概率以及辐照次数的统计性研究，并结合单脉冲辐照的结果，说明了存在于薄膜中微小的缺陷参与了多脉冲激光对薄膜的损伤过程,得到了制备IBS高反射膜的损伤阈值和照射次数的关系式，用Nomarski偏光显微镜观察了实验过程中样品的损伤形貌，发现是典型的缺陷损伤.

Accumulation Effect of Multi-shot Laser-induced Damage to Optical Coatings

Accumulation effect of multi-shot laser-induced damage to optical coatings was investigated. Laser damage testing was performed at 1064 nm with nanosecond pulses at a pulse length of 12 ns, using an accurate and reliable measurement system. Damage threshold and the number of shots were studied by a statistical method. Comparing the case of single-shot with multi-shot laser damage, it is known that microdefects in the optical coatings were responsible for multiple pulses damage to mirrors. The damage mechanism was used to explain the damage process. The expression for the damage threshold and the number of shots was founded. Nomarski microscope was employed to observe laser-induced damage morphology after laser irradiation.