引入过渡层提高介质减反膜的抗激光损伤阈值

提出了一种用于提高介质减反膜的损伤阈值的新的方法，在H2.5L (H:HfO2, L:SiO2)的膜层与基底之间引入4个1/4光学厚度的SiO2薄膜，发现抗激光损伤阈值提高了50%，并且保持1064nm处的反射率低于0.09%。本文分析了造成这一提高的机制，一定厚度的氧化硅过渡层的引入是一种提高介质减反膜的损伤阈值的灵活有效的方法。

A new method for increasing laser induced damage threshold (LIDT) of dielectric antireflection (AR) coating is proposed. Compared with AR film stack of H2.5L (H:HfO2, L:SiO2) on BK7 substance, SiO2 interfacial layer with four quarter wavelength optical thickness (QWOT) is deposited on the substrate before the preparation of H2.5L film. It is found that the introduction of SiO2 interfacial layer with a certain thickness is effective and flexible to increase the LIDT of dielectric AR coatings. The measured LIDT is enhanced by about 50%, while remaining the low reflectivity with less than 0.09% at the center wavelength of 1064 nm. Detailed mechanisms of the LIDT enhancement are discussed.