针对激光诱导K9玻璃元件体损伤问题,利用在线成像技术获得激光诱导体损伤时的侧面和正面图像,并分析体损伤中成丝损伤的特点及成丝损伤中成核损伤和裂纹对损伤增长的影响。结果表明,当激光辐照能量大于体损伤阈值时,体损伤会以成丝损伤、成核损伤及损伤增长的形式出现,但只有最靠近入射激光方向的成核损伤点会在后续激光辐照下出现持续增长现象。成核损伤在损伤增长过程中的裂纹更多向纵向和逆激光传播方向扩展。同时,在相同能量的激光辐照下,损伤面积的增长强烈依赖于成丝损伤点的长度,且从侧面方向观察到的损伤点的损伤增长系数大于从正面方向观察到的。研究结果为对K9玻璃元件体损伤及其在后续激光辐照下的损伤增长规律研究提供了参考性。

To address the problem of bulk damage of K9 optical components induced by laser irradiation, the on-line imaging technology is used to obtain front- and side-view images of laser-induced bulk damage. The characteristics of filament damage in bulk damage, influence of nucleation damage in filament damage, and effect of crack on damage growth are investigated. Results indicate that when the irradiation energy is larger than the bulk damage threshold, the bulk damage appear in the forms of filament damage, nucleation damage, and damage growth. However, only the nucleation damage site closest to the direction of the incident laser beam continues to grow under subsequent laser irradiation. Moreover, in the damage-growth process, the cracks of nucleation damage propagate along the longitudinal and reverse directions of propagation of the laser beam. Further, under the same laser irradiation, the growth of damage area strongly depends on the length of the filament damage site. Moreover, the damage-growth coefficient of the damage site observed in the side direction is larger than that observed in the front direction. These results can provide a reference for investigating bulk damage and damage growth mechanisms under subsequent laser irradiation of K9 optical components.