为了探究激光预辐照的工艺参数对提高光学薄膜抗激光损伤性能的影响,在1064nm的Nd∶YAG激光器组成的薄膜阈值测试平台上,对电子束热蒸发镀制的ZrO2单层薄膜进行了小光斑扫描的激光预处理.研究了不同能量阶单次扫描、单一能量阶多次扫描及不同能量阶多次扫描的激光预辐照对薄膜损伤阈值的提高效果.结果表明:不同能量阶单次扫描中,提高阈值效果最好的是采用原始样片损伤阈值的39%的能量扫描,可提高阈值13%;采用39%的阈值能量阶进行了多次预辐照实验,扫描3次效果最好,阈值提高了56%;在能量递增的多次预辐照实验中,递增能量多次预辐照与单一能量阶多次预辐照的预处理效果相似.
To study the effect of laser condition parameters on improvement of laser induced damage threshold(LIDT) of optical thin films and find the proper parameters,the authors adopted small beam raster scanning for laser-condition of ZrO2 thin film deposited by electron beam evaporation,operating at the Nd∶YAG harmonic wavelengths of 1 064 nm.On a automatic testing and conditioning system of laser induced damage for optics,the improvement of LIDT after laser conditioning by the means of single shot at different energy steps,multi-shots at one energy step and multi-shots at increasing energy step were compared.The LIDT of the sample being shot one time with 39% energy has increased 13%.The LIDT of samples,which were irradiated 3 times under the energe of 40%,can improve 56%.The improvement of LIDT on n-step laser conditioning is similar to the mode of multi-shot at one energy step,so laser conditioning by the means of multi-shots at single energy step can improve the LIDT of optical films and optics efficiently.