高性能偏振膜的研制

综述了国内外科研人员在高性能偏振膜的研制方面开展的工作,主要涉及偏振膜光谱性能、抗激光损伤阈值和膜层应力控制等方面的研究。针对我国神光系列装置对偏振膜的性能要求,简述了中国科学院上海光学精密机械研究所采用电子束沉积技术在光谱性能、损伤阈值和面形精度三个方面开展的研究工作。给出了在薄膜设计、制备和后处理等方面进行的研究和取得的进展。结合上述研究成果,得到了低缺陷密度、低应力的高性能偏振膜。由本科研团队研制的布儒斯特角薄膜偏振器在在2012年和2013年SPIE激光损伤国际会议(SPIE Laser Damage)组织的全球性偏振膜激光损伤阈值水平竞赛中连续取得了p分量损伤阈值和平均损伤阈值最佳的结果。另外,通过解决应力诱导膜层龟裂的重大技术问题,在国内首先推出了大口径偏振片,该大口径偏振片满足透射率TP98%,反射率RS99%的光谱性能要求和17J/cm2(9ns)的通量运行要求,有力支撑了我国SGII-UP大型激光装置的稳定运行。

Development of high performance polarizer coatings

The research and achievements of high performance polarizer coatings by many scholars around the world are reviewed, including the spectral properties, laser damage threshold and stress control. For the performance requirements of polarizer coatings in China Shenguang series facilities, it describes the investigation of spectral properties, laser damage threshold, and figure accuracy of the polarizer coatings based on electron beam depolarization by Shanghai Institute of Opitcs and Fine Mechanics of the Chinese Academy of Sciences(SIOM). Much work and achievements on design, preparation and past-treatment of the coating are given. On the basis of the research achievements, high performance thin films polarizer with low defect density and low stress have obtained. The Brewster angle thin film polarizer developed by our team has participated in the International Laser Damage Competition held on the SPIE 2012 Laser Damage & SPIE 2013 Laser Damage Symposium. The p-polarized LIDT(Laser Induced Damage Threshold) as well as the average of p-polarized and s-polarized LIDT achieves the best results. The stress-induced crazing of large aperture polarizer coating is also solved, by which the manufacturing of large aperture polarizer is implemented in China, showing the spectral properties of T_P>98%,R_S>99% and the flux property of 17 J/cm²(9 ns).Now, the prepared large aperture polarizer has supported the stable operation of ShenguangII-UP laser facility.