高损伤阈值双色膜

Bichromatic coatings with high laser-induced damage threshold

结合双色膜的驻波场分布优化膜系设计,以电子束蒸发的方式制备了1 064 nm高透过、532 nm高反射的HfO2/SiO2双色膜。采用1-on-1方式测量了双色膜在基频透过光和倍频反射光的辐照下的损伤阈值,为了研究双色膜在基频和倍频下的损伤机制差异,对比了双色膜不同的初始损伤形貌并分析了其形成原因。针对损伤机制的差异,研究了外层驻波场分布对于倍频反射光辐照下的双色膜损伤特性影响以及氧化硅内保护层对于基频透过光的损伤特性的影响。实验结果表明:氧化硅内保护层和驻波场优化有助于提高双色膜在基频光和倍频光辐照下的激光损伤阈值,并对其机理做了分析。

1 064 nm AR/532 nm HR bichromatic coatings designed by optimizing the electric field distribution of the film stacks were fabraicated using electron beam evaporation technique.To study the different damage behaviors of biochromatic coatings under the irradiation of 1 053 nm and 527 nm,the 1-on-1 laser damage threholds of the coatings were measured and the initial laser-induced damage morphologies of the coatings were recorded respectively after each shot.The damage morphologies of the coatings showed that the origin of damage were different under the irradiation of 1 053 nm and 527 nm.Due to the different damage mechanisms,the influence of SiO2 barrier layer on the 1ω laser-induced damage and electric distribution on the 2ω laser-induced damage were studied.It is found that the introduction of SiO2 barrier layer and electric distribution optimzing can increase the laser induced damage threshold（LIDT） of 1 064 nm AR coatings and 532 nm HR coatings respectively.Meanwhile,the relevant mechanisms for 1ω and 2ω laser-induced damage threshold are also discussed.