偏振分光膜中节瘤的激光损伤特性

Laser induced damage characteristics of nodules in thin-film polarizers

研究了1 064 nm Hf O2/Si O2偏振分光膜中节瘤的损伤特性。为了研究偏振分光膜中节瘤缺陷种子源粒径大小与损伤阈值之间的关系,在熔石英基板上植入了尺寸和密度可控的单分散性的Si O2小球,并采用电子束蒸发技术在熔石英基板上制备了1 064 nm Hf O2/Si O2偏振分光膜。为了便于损伤测试,节瘤缺陷密度控制在20～40 mm2左右,并采取旋涂的措施防止了Si O2小球团聚的现象。为了获得人工节瘤损伤能量的统计值,用脉宽为10 ns的1 064 nm脉冲激光进行了光栅扫描式损伤测试。实验结果表明在偏振分光膜中节瘤缺陷的损伤阈值随着种子源粒径的增大而单调下降。

In this paper the laser damage characteristics of nodule defects in 1 064 nm HfOJSiOz polarizers was discussed. To find the correlation between the seed diameter and the damage threshold of nodular defects in thin-film polarizers, monodisperse SiO2 microspheres were implanted on quartz substrates, and 1 064 nm HfOdSiO2 polarizers were fabricated on quartz substrates by using electron beam evaporation deposition technique. The defect density of nodules that were created from SiO2 microspheres was purposely controlled to be around 20-40 mm2 and spin coating was taken to minimize clusters of SiO2 microspheres. To get the statistical value of ejection fluences of these engineered nodules, a raster scan damage test was used with a pulse width of 10 ns 1 064 nm laser. Laser damage test results showed that in thin-film polarizers the ejection fluences of nodules monotonically decrease with the increase of silica microsphere diameter.