| In recent years, with the development of the laser polarization technology, polarization device has become the important components of the development of polarizing technology, and it is widely used in laser polarization technology at home and abroad. It is also one of the important components with wide range of applications of the optical fiber communication, laser modulation, optical information processing, biological tissue research, and many other areas. Polarization devices especially high-precision polarization device, are usually made of natural or artificial crystal, The nature crystal account for quite a large part. The artificial crystal still cannot meet the quantity and quality of device performance requirements. This has been concern of the people a long time. Very little nature crystal can reach the optical quality, and it is very expensive, Generally, it has different levels of impurities and fluorescence phenomenon. This is a scientific research and production problem urgently to be solved. It makes people have to pay attention to natural crystal with defects. This article through analyze the prism extinction which is the important performance parameter of the polarizing device, as the breakthrough point. An experimental basis which can be identify the materials be used is proposed. In this paper, the interference factors to the maximum intensity of the polarizing prism is analyzed, and the accurate determination of extinction ratio system is also improved. It is verified the influence of the scattering crystal light to the extinction ratio in theoretical and experiment, and provides some Suggestions for people to use scattering crystals.In this paper, on the basis of the predecessors, the accurate determination of the extinction ratio be improved. In terms of the scattering crystal, two aspects of theoretical derivation and experimental verification was analyzed. Generally, this paper includes several aspects of the following content:The first chapter briefly introduces the meaning of the precise determination of the extinction ratio and the effects of the scattering to the extinction ratio.The second chapter gives the concept of Iceland crystals material performance, the design principle of the prism and the intelligent method to measure extinction ratio. This chapter content is the basis for the subsequent research part, and most related content is the public information and means.The third chapter and the fourth chapter is the core part of this article, and it is also the place of innovation of this paper, independently.Light intensity of the transmission curve is not completely in accordance with the cosine square curve rule changing by using highly extinction ratio measuring system,some ups and downs on the curve will seriously affect the minimum intensity of transmission coefficient and the maximum intensity of light transmission coefficient precise values,which affects the accuracy of extinction ratio of ρ = T2 / T1.For this point,we can locate the interference factors affecting transmission curve with the physical optics method and theoretical analysis of each part of the prism transmission rate,and then adopt the method of curve fitting to the experimental curve fitting, after that calculate the position of the extremum points, then stepping motor will be dispatched to the location to measure the location of the light intensity. The experiment results show that this method has improved the extinction ratio measurement precision.The fourth chapter analysis the method to measure Mueller matrix of the four types air-gap Glan-Taylor prism,which include red line furuncle lump crystal, red line scattering crystals, the green line furuncle crystals and crystal green line scattering, and gives the results of the experiment,and calculates the extinction ratio by formula.Then the optimization of the intelligent extinction ratio system which is described in the third chapter is used to measure the above four prism and the normal prism.Comparing the results of the two methods and comparing to the results of the normal prism, it turned out that the magnitude of the extinction ratio is10-5.This confirmed the results is reliable. According to the four types prism above, analyzed the factors, the effects to the scattering intensity were analysed. Combined with a large number of experiments, we think that scattering effects is exist, but the influence is limited. The prism is made of scattering materials, its extinction ratio is still 10-5.Main work and contributions of this paper lie in:1、the extinction ratio measurement system is improved on the basis of the predecessors.2、Mueller matrix is used to analysis the extinction ratio of the four types Glan-Taylor prism,which is made of scattering crystal. Through the experiment to measure extinction ratio, it clarified the influence degree of the scattering. |
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