预填充聚苯乙烯控制SiO_2/ZrO_2薄膜膜间渗透

Infiltrating control of SiO_2/ZrO_2 sol-gel films by pre-filled polystyrene

提出预填充方式控制膜间渗透,采用聚苯乙烯(PS)对低折射率SiO2膜内孔隙进行预填充,镀第2层ZrO2后再于甲苯中洗脱,恢复孔隙率以实现膜间防渗透。采用椭偏仪、紫外-可见光分光光度计、原子力显微镜(AFM)和光学显微镜对薄膜进行表征,研究了预填充PS前后的溶胶-凝胶SiO2/ZrO2薄膜膜间渗透与激光辐照损伤。结果表明,单层SiO2填充PS后膜面均方根粗糙度由4.164 nm下降为1.983 nm,折射率由1.1474增加到1.358 3,在甲苯中浸泡15 min后可完全清除PS。PS填充后的SiO2/ZrO2双层膜清洗1 h后,可使填充了PS的SiO2层的平均折射率由1.36降为1.29(未填充区域为1.38),透光率峰值提高(1～2)%。利用Nd:YAG激光器(1.064μm,8.1 ns)对SiO2/ZrO2双层膜进行了损伤阈值的测试,结果表明经PS填充并清洗后损伤阈值降低了8 J/cm2,但两者损伤形貌均为熔融型。

A pre-filling method is proposed to prevent infiltrating. The ZrO2 film is deposited on the predeposited and polystyrene （PS）-filled SlOe film. Then the PS is washed away by dipping in toluene in order to revive the micro-holes of the SiO2 film. At the same time,the infiltrating is restricted. Ellipometry, UV-VIS spectroscopy,atomic force microscopy （AFM） and optical microscopy are used to characterize the thin films. The infiltrating behaviour and laser-induced damage threshold （LIDT） of two-layer sob gel SiO2/ZrO2 thin films are studied. The results show that the refractive index of the single layer PS- filled SlOe increases from 1. 1474 to 1. 358 3,while the surface roughness decreases from 4. 164 nm to 1. 983 nm after PS is filled. The PS is washed away completely by dipping in toluene for 15 mins. To the two-layer SiO2/ZrO2 films,the average refractive index of the infiltrated layer decreases from 1.38 to 1.29 and the tramsmittance peak value is improved by （1 -2）% after PS-filling and washing for 1 hour. The LIDT of the two layer films is measured by Nd：YAG laser beam （1. 064 μm,8. 1 ns）. The LIDT reduces by 8 J/cme for the PS-filled and washed SiO2/ZrO2 films. Similar to the unfilled film,the damage morphologies of the PS-filled and washed film are mainly ablation.