激光预处理对BaF_2薄膜损伤性能的影响

Influence of Laser-conditioning on Laser Induced Damage Capability of BaF_2 Thin Films

为了提高光学薄膜元件抗激光损伤的能力,除了寻找先进的镀膜方法及工艺外,还可采取后期处理,因为后期处理对激光损伤阈值(LIDT)也有重要影响。采用输出波长为1064nm的调Q Nd:YAG激光器,对膜厚为λ/2(λ=1064nm)的单层BaF2薄膜进行激光预处理,研究了其激光损伤特性。在光斑大小一定的条件下,改变能量密度和脉冲次数,分别研究了它们对薄膜阈值的影响,得出最佳处理参数:能量密度为9.9J/cm2,脉冲次数为3次。处理后的BaF2薄膜,激光损伤阈值从未处理的16.5J/cm2提高到了29.9J/cm2。

In order to enhance the laser induced damage capability of optical films components, besides advanced methods and processes, post-treatment has significant influence on the laser induced damage threshold （LIDT） of thin films. Q switch Nd：YAG laser of the working wave length at 1064 nm,was used to post process on BaF2 single layers with thickness of λ/2（λ= 1064 nm） deposited by electron beam evaporation, and the laser induced damage properties were investigated. By changing the energy density and pulse number under the spot size remained a fixed value, their effects on thin films damage threshold were studied respectively, the optimal processing parameters were obtained： ener-gy density is 9.9 J/cm^2 and pulse number is 3 times. The LIDT of post processed BaFz films was improved from 16.5 J/ cm^2 to 29.9 J/cm^2.