消偏振薄膜的设计和制备
文献类型：学位论文
| 作者 | 王晴云 |
| 学位类别 | 硕士 |
| 答辩日期 | 2010 |
| 授予单位 | 中国科学院上海光学精密机械研究所 |
| 导师 | 齐红基 |
| 关键词 | 薄膜 消偏振 倾斜沉积 双折射 离子束溅射 |
| 其他题名 | Design and Preparation of Non-polarizing Thin Films |
| 中文摘要 | 当光线从一种介质斜入射到另一种介质时，由于电场和磁场的切向连续，不可避免的会出现偏振分离。光线的斜入射在现代光学系统中很常见，但在很多领域这种偏振分离是不允许的，例如在空间遥感领域就要求消除不同偏振态之间的分离，以便取得准确的目标辐射数据，在投影系统中为了得到更好的演示效果，也需要消除偏振分离。在一些光学系统中偏振分离甚至会导致系统无法正常运行，所以必须寻找一种有效的方法减少甚至消除斜入射条件下的偏振分离情况。 本文基于各向同性和各向异性多层介质薄膜材料，设计并制备了消偏振薄膜，并对薄膜进行了测试和分析。对于各向同性材料，使用三种镀膜材料，可以获得较好的消偏振设计和制备效果。对于各向异性材料，利用倾斜角沉积技术，仅仅使用单一材料即可实现消偏振效果。 首先运用电子束蒸发制备了不同沉积角下TiO2单层膜，用SEM观察了制备TiO2单层膜的微结构，结果显示各个角度沉积的薄膜都有不同倾斜角度的柱状结构。使用分光光度计测量薄膜透过率，用包络法及计算机优化方法获得薄膜对于不同偏振态光波的折射率色散情况。发现不同沉积角度下材料的折射率色散情况差别较大，为使用单一材料制备多层薄膜提供了材料基础。通过选择沉积角度及材料沉积面的控制，使制备薄膜在0°入射时S偏振光的反射带宽小于P偏振光的反射带宽。由于入射角度增加，薄膜对于S偏振光的反射带宽增加，而对于P偏振光反射带宽减少，寻找合适的角度满足S和P偏振光反射率带宽基本相同的要求，从而达到消偏振目的。采用这一思想，我们设计和镀制了消偏振反射膜和消偏振长波通薄膜。此外，还利用雕塑膜的双折射特性制备了λ/4波片和 0°入射起偏薄膜。 同时综合Costich和Thelen薄膜设计思想，利用Needle优化算法设计并制备了中心波长为1064nm，带宽为20nm的消偏振分光膜，并对制备误差进行分析。消偏振薄膜使用三种各向同性材料，Ta2O5，Al2O3和SiO2，为此，对Al2O3离子束溅射的沉积工艺进行了研究，探讨了不同工艺参数对薄膜光学性质影响，并得到优化的工艺参数。 |
| 英文摘要 | When light propagates from one medium to another at oblique angle, polarization effect arises inevitably due to tangential continuity of electromagnetic fields. In modern optical systems, oblique incidence is common, but the polarization separation is not permitted in many applications, such as the space remote sensing areas and projection system. In some optical system, polarization effects even can result in failure of system. Therefore, some approaches should be proposed to eliminate the effect of polarization separation. With isotropic and anisotropic dielectric materials, non-polarizing thin films were designed, prepared and measured. Some results of measurement and analysis were also presented. With isotropic dielectric materials, it shows perfect non-polarizing effect measured with spectrometer. The non-polarizing thin film with a single material gives good non-polarizing effect with glancing angle deposition technique. First, several titanium sculptured single layers were prepared with different deposited angles by electron beam evaporation. The cross-section images of films show oblique columnar structures, observed by SEM. The transmittance spectra, measured with spectrometer, were used to extract the refractive index dispersion for two polarizations by envelope method and optimization method. The result shows the strong dependence of refractive index dispersions on the deposited angles, which indicates the possibility of non-polarizing film with a single material. With appropriate deposited angles and deposited planes, the film shows smaller reflected bandwidth for S polarization, compared with P polarization at the normal incidence. The reflected band shrinks for P polarization but extends for S polarization with the increase of the incidence angle. Therefore, the reflected bands of thin film are almost same for S and P polarizations at an appropriate incident angle, and the non-polarizing design is achieved. Based on this idea, non-polarizing long-wave pass film and high reflectance film were designed and prepared. Meanwhile λ/4 wave plate and polarizing film at normal incidence were deposited. Based on Costich and Thelen theories, non-polarizing beam-splitter at 1064nm were designed and prepared. The materials, Ta2O5, Al2O3 and SiO2 were used for non-polarizing film. The deposition parameters were optimized for Al2O3 target before the preparation of non-polarizing film. |
| 语种 | 中文 |
| 源URL | [http://ir.siom.ac.cn/handle/181231/16681]  |
| 专题 | 上海光学精密机械研究所_学位论文 |
| 推荐引用方式 GB/T 7714 | 王晴云. 消偏振薄膜的设计和制备[D]. 中国科学院上海光学精密机械研究所. 2010. |
入库方式： OAI收割
来源：上海光学精密机械研究所
浏览0
下载0
收藏0
其他版本
除非特别说明，本系统中所有内容都受版权保护，并保留所有权利。