摘要
介质膜反射镜是星载激光测高仪系统中不可缺少的薄膜元件,其面形质量直接影响探测系统测距的分辨率和精度.本文采用离子束辅助电子束蒸发工艺在石英基底上沉积Ta2O5/SiO2多层反射膜,并在200—600℃的空气中做退火处理.通过X射线衍射、原子力显微镜、分光光度计及激光干涉仪等测试手段,系统研究了退火温度对Ta2O5/SiO2多层反射膜结构、光学性能以及应力特性的影响.结果表明:Ta2O5/SiO2多层反射膜退火后,膜层结构保持稳定,膜层表面粗糙度得到有效改善;反射膜在500—600℃退火后,残余应力由压应力向张应力转变;采用合适的退火温度可以有效释放Ta2O5/SiO2薄膜的残余应力,使薄膜与基底构成的介质膜反射镜具有较好的面形精度.本文的实验结果对退火工艺在介质膜反射镜面形控制技术方面的应用具有重要意义.
In the optical system of spaceborne laser altimeter,dielectric mirror is an indispensable optical film element.Its surface shape quality directly affects the resolution and accuracy of distance measurement of the detection system.It is pressing and necessary to carry out research on the surface shape control technology of dielectric mirror to eliminate or reduce the effect of film stress on surface shape.The Ta2O5/SiO2 multilayer reflective coatings are deposited on quartz substrates by using the ion beam assisted electron beam evaporation(IBE),and then annealed in air in a temperature range from 200 to 600℃.The effect of annealing temperature on the structure,optical and stress properties of Ta2O5/SiO2 multilayer reflective coatings are systemically investigated by using x-ray diffraction,atomic force microscope,spectrophotometer and laser interferometer.The results show that all the Ta2O5/SiO2 multilayer reflective coatings,after being annealed,are amorphous in structure.The annealing temperature has a great influence on the surface roughness of reflective coating.With the increase of annealing temperature,the surface roughness of reflective coating first decreases and then gradually increases,but is still smaller than that of as-deposited sample.After being annealed,the reflectance spectrum of reflective coating shifts slightly toward the long-wave direction,and the reflectivity increases a little.When being annealed at 500-600℃,the compressive stress of reflective coating could be transformed into tensile stress,and the surface is changed from convex to concave shape.It can be concluded that annealing at an appropriate temperature can effectively release residual stress of Ta2O5/SiO2 multilayer reflective coating and eliminate the deformation of substrate caused by film stress,and thus improving the surface shape quality of dielectric mirror.,After being annealed,the reflective coating still possesses the stable structure and spectral properties,so that dielectric mirror can meet the application requirements of spaceborne laser altimeter.In this paper,the experimental results are of great significance for applying the annealing technology to the surface shape control technology of dielectric mirrors.
作者
刘保剑
段微波
李大琪
余德明
陈刚
王天洪
刘定权
Liu Bao-Jian;Duan Wei-Bo;Li Da-Qi;Yu De-Ming;Chen Gang;Wang Tian-Hong;Liu Ding-Quan(Shanghai Institute of Technical Physics,Chinese Academy of Sciences,Shanghai 200083,China)
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2019年第11期172-178,共7页
Acta Physica Sinica
基金
国家自然科学基金青年科学基金(批准号:61605229)
中国科学院上海技术物理研究所创新专项基金(批准号:CX-129)资助的课题~~
