旋涂法制备KDP晶体减反膜

对KDP晶体旋转涂膜过程中的技术问题进行了探讨，包括元件夹持安全性、膜层均匀性、膜层透射比、膜层疏水性能、膜层激光损伤阈值等。分析了晶体元件加速旋转阶段的受力情况，明确了KDP晶体元件在旋涂操作过程中受力状态的安全性。对不同溶剂体系的膜层均匀性进行了判断，在400 mm尺寸的元件上获得了透射比均匀性为0.3%的减反膜。对溶胶进行稳态剪切流变分析得知，在现有的涂膜转速 (对应剪切速率100~200 s-1)范围内，其粘度随着剪切速率的增加几乎不变，近似牛顿流体。在旋涂过程中，处于基底不同位置的溶胶的粘度大致相等，这是影响膜层均匀性的重要原因之一。膜层疏水性能较好，水接触角测试结果大于152。在SiO2基底上制备的减反膜，1053 nm处透射比大于99.8%。在熔石英基片上制备的三倍频减反膜样品的功能性激光损伤阈值约为10 J/cm2（355 nm, 3 ns）。

KDP crystal antireflective coatings prepared by spin coating method

The KDP crystal antireflective coatings prepared by spin coating method were discussed. The coating was modified using hexamethyl disilazane (HMDS), and had good moisture-resistant property. Some technique problems such as clamping safety during the spin process were analysed. The coating uniformity, the transmittance, moisture-resistant property and the laser induced damage threshold (LIDT) were measured. The transmittance ununiformity of the coating was about 0.3%, the transmittance at 1053 nm was over 99.8%, the water contact angle was over 152, and the LIDT was about 10 J/cm2 (355 nm, 3 ns).