单元反射型偏光分束棱镜的设计

【作者】 倪志波；

【导师】 宋连科；

【作者基本信息】 曲阜师范大学 ， 光学， 2007， 硕士

【摘要】 反射型偏光分束棱镜是根据双折射晶体表面的双反射现象设计的一类新的偏光器件，这类棱镜的特点是集偏光分束与光传播的变向于一身，在偏光分束的同时，可以使光的传播方向改变一定的角度。目前的几种双反射偏光分束棱镜多采用二元结构，由于胶合层的存在，使得这几种棱镜的光强透射比普遍偏低。本文借鉴了它们的部分设计思想，研制了两种单元结构的反射型偏光棱镜，并对其光学性能进行了理论分析和性能测试，全文概括起来主要有以下几部分：第一章绪论部分，主要介绍了偏光器件的分类、性能和应用范围，并对本文的工作进行了说明。第二章首先给出了部分基础理论知识，然后详细介绍了起偏棱镜和偏光分束棱镜的种类、设计思想和性能参数，并对相位延迟器件、退偏器件和冰洲石晶体偏光棱镜设计概要进行了简单的介绍。论文的后三章是本文的核心内容，也是我的主要工作。这三章对单元结构双反射偏光棱镜的结构、性能参数作了详细的理论分析，并进行了实验测试：首先我们根据冰洲石晶体的双折射性质，提出了Ⅰ、Ⅱ两种类型五种不同结构的单元双反射偏光分束棱镜的设计构想。理论分析证实，这五种结构的单元双反射偏光分束棱镜都可以使两束出射光等分束角输出，并且找到了实现等角分束的最佳结构角。在结构固定后，我们对各棱镜的性能，如分束角不对称度随入射角和入射波长的变化关系，光强透射比随波长的变化关系等进行了理论分析。通过棱镜性能的比较，我们选择了其中两种性能最好的棱镜作为Ⅰ、Ⅱ两种类型的代表加工成样品，并对样品进行了实验测试。从分束光不对称度和光强透射比随入射角、入射波长变化的实验数据可以看出，虽然测试数据在一些点上与理论结果相比有所偏离，但两者总体趋势基本一致，特别是从分束角不对称度随入射角变化的实验值和理论值的对比中，可以更清楚地看到这一点。通过对棱镜进行消光比测试发现，两出射光束中，o光的消光比性能要优于e光的消光比性能，但两束光的消光比性能都不低于10^-5，具有实际应用价值。理论分析和实验测试结果均表明：Ⅰ、Ⅱ两种类型的单元双反射偏光分束棱镜都具有较好的性能，较高的实用价值。本文的主要创新之处在于：提出了新的单元双反射偏光分束棱镜的设计方案，从理论上进行了详细的推导，并结合实验对器件设计性能进行了验证分析。更多还原

【Abstract】 Refractive prisms which are designed basing on birefringent character on surface of calcite crystal are new patterns of prisms. Not only can they split o and e light which are both linearly polarized light, but also can change the propagating directions of o and e light. At present, there are several patterns of refractive prisms, most of which are composed of two parts. For the existence of cementing layer, the transmission of light is not very high. In order to improve the transmission of light, two new patterns which have only one part are designed in my paper. Some of the design ideology is drawn lessons from the old patterns. Basing on theory analysis and experimental measurement, we analyse the two patterns’ optical performances. The full text includes the following contest briefly.In the first chapter, some basic knowledge, such as species and performances of polarizing prism, fields of application and so on, are explained and then is the introduction of the main content of this paper.Some basic theories of polarizing devices are recommended at the beginning of the second chapter. After that detailed explanation of polarizing prisms and beam splitting prisms, including species, design ideologies and performance parameters, is done. Finally, we illustrate some other knowledge related to prism, such as phase delay devices, depolarizing devices and main points of prism designation which is especially important for prism made of calcite crystal.The last three chapters are the focal points in my paper and also my work. Some important parameters of the prisms we designed are analysed in full, such as structures, optical performances and so on. Of cause, detailed experimental measurements are very necessary. First of all, two new prisms including five different structures, which are all modular construction and can split light by double reflective property of calcite crystal, are tendered. Theory analysis turns out that, each prism can make sure that the two light’s emergence angles are equal. After prisms’ structures are fixed, some important parameters of each prism are analysed, such as how splitting angle’s asymmetry and transmission of light varied when incidence angle and incidence wave length are changed. Comparing the performances of these prisms, two prisms which have better performances and can represent the two patterns considered above are processed. Though comparison of experimental results and theory results, we can conclude that, although deviation is exist, the basic tendency is still coincident, especially from the comparison of experimental data and theory data which can render the variation of splitting angle’s asymmetry when incidence angles are changed. From testing of extinction ratio we can find that, the extinction ratio of o light is prior than the extinction ratio of e light, but both of them are higher than 10^-5.Both of the results of theory analysis and experimental testing are all illustrated that, the performances of these two prisms basing on double reflection are quite well and they can be used in several field.The main innovations of this article are that: we put forward a new design idea of prism. This new prism is basing on double refraction and has only one part. After theory analysis in full, the performances of the prism are certified by experiment.更多还原