Uniaxial Crystal With Negative Refraction Development Of The New Polarized Devices

Polarized optics has become one of the important branches of optics since Malus found the polarization of light in 1808.Polarization devices are the fundamental elements of the polarized light information processing and the polarized light technique application,and the crystal prism has been widely applied due to its high extinction contrast,transmissivity,and anti-sun damage ability.Especially since 1960s,with the emergence of laser,the crystal prism has played a function which can not be replaced in the application of laser polarization technology.At present,polarization prism with high performance is mainly made by Iceland crystal,which is a kind of natural uniaxial crystal,namely the calcite crystal with achromatic color, transparency and purity.This crystal was firstly found in Iceland,so it is called Iceland crystal. The Iceland crystal is difficult to find and the price of it is very high.Negative refraction is a newly-used concept with the development of the left-handed materials, which was firstly proposed by V.G.Veselago.In recent years the research of left handed materials has got some essential development,and research of negative refraction has also achieved a rapid development.The negative refraction in uniaxial crystal is different from that in left-handed materials,it is one special property of the uniaxial crystal,and the other one is negative reflection.In this paper,based on the negative refraction in uniaxial crystal,we designed two new kinds of unit polarization beam splitter prism.There are several parts in this paper as follow:In chapterⅠ,we firstly introduced some characteristics of crystal polarization prism in common use at present,and then discussed the significance of our design.In the chapterⅡ,we depicted the principles of the left handed material,negative refraction, and polarization prism.The concept of the left handed material and negative refraction their latest international development were introduced.We deduced the principle of negative refraction and negative reflection.And the operating principle of some prisms in common use was introduced and their strengths and weakness are analyzed later.ChapterⅢandⅣare the body of this paper,which are also the innovation of it.In chapterⅢwe depicted the design of two new kinds of unit polarization beam splitter prism based on the negative refraction in uniaxial crystal of new type,made a concrete analysis of the mode of the design in theory.In this chapter,firstly we put forward two modes of design of new type prisms.Then according to the Fermat's principle and coordinate translation method which were deduced from null geodesic equation of light in metric transformation,we derived the refraction and reflection equations that e-rays incident to the uniaxial crystal media from airs and to the airs from the uniaxial crystal,as well as at the interface of the internal reflection.These formulas offered a theoretical basis for prism design and calculating the splitting angle of prism.Due to those formulas,we designed the single unit extraordinary refraction Rochon prism which was similar to the Rochon prism and unit negative refraction prism,similar to the Wollaston prism.Moreover, we derived the related formula for the new type prisms' splitting angle,and drew the theory curve of splitting angle prism with the angle of incidence,crystal optical axis angle and the incident wave length.In chapterⅣ,we did experiment to test the performance of new-type prisms.Firstly,according to the designs,we made four sample prisms,among which three are the single unit extraordinary refraction Rochon prism with different crystal optical axis angle,and one is the single unit negative refraction prism with 45°crystal optical axis.The 0.5" angular instrument was applied to establish the test optical path,and the lasers with 633nm and 532nm were used to test the splitting angle and splitting angle prism with the angle of incidence of the four samples.The test result agreed with the calculation.The analysis showed:the slight error is mainly from the angular error existed in the manufacturing process of the samples.