Appl Opt. 2023 Mar 1;62(7):B126-B132. doi: 10.1364/AO.477054.
The peak power of high-power laser facilities is limited by the laser-induced damage to the final optical components. Also, when a damage site is generated, the damage growth phenomenon limits the lifetime of the component. Many studies have been performed to improve the laser-induced damage threshold of these components. The question now arises as to whether improvement of the initiation threshold leads to a reduction of the damage growth phenomenon. To address this question, we performed damage growth experiments on three different multilayer dielectric mirror designs exhibiting different damage thresholds. We used classical quarter-wave designs and optimized designs. The experiments were carried out with a spatial top-hat beam, spectrally centered at 1053 nm with a pulse duration of 0.8 ps in - and -polarization. The results showed the impact of design on the improvement of the damage growth thresholds and a reduction of the damage growth rates. A numerical model was used to simulate damage growth sequences. The results reveal similar trends to those observed experimentally. On the basis of these three cases, we have shown that improvement of the initiation threshold through a modification of the mirror design can lead to the reduction of the damage growth phenomenon.
高功率激光设施的峰值功率受到最终光学元件的激光诱导损伤的限制。此外，当损伤部位产生时，损伤增长现象会限制元件的寿命。已经进行了许多研究来提高这些元件的激光诱导损伤阈值。现在的问题是，提高起始阈值是否会导致损伤增长现象的减少。为了解决这个问题，我们在三种具有不同损伤阈值的不同多层介质镜设计上进行了损伤增长实验。我们使用了经典的四分之一波设计和优化设计。实验采用空间平顶光束进行，光谱中心位于 1053nm，偏振为-，脉冲持续时间为 0.8ps。结果表明，设计对改善损伤增长阈值和降低损伤增长速率有影响。使用数值模型模拟了损伤增长序列。结果显示出与实验观察到的相似趋势。基于这三种情况，我们已经表明，通过改变镜子设计来提高起始阈值可以导致损伤增长现象的减少。
