Research Of Digital Method To Measure For The Polarization Aberration Of Pechan Prism

Pechan prism is composed of Schmidt Prism and half-penta prism. The research show of recent years that the exit of linearly polarized light came across of Pechan Prism is elliptically polarized light, and even of, two different elliptically polarized light--polarization aberration. The result of polarization aberration is Schmidt prism made two different propagation path. And the difference of spatial position of two different path roof surface made the difference of transmitting characteristics of polarization. The research of this essay is coming from measurement and characterization of polarization aberration of Schmidt prism that is the part of Pechan prism. The purpose of this dissertation is to find a quantitative way of measuring the polarization aberration of Schmidt prism.The matrix optics and physical optics are the theoretical basis of the article research. Through the characterization of the method of the lightwave polarization state, the optical element of Mueller matrix and Jones matrix comparative and analysis, it clears that Mueller matrix is appropriate method to analysis Polarized light, unpolarized light and Partially polarized light. We used the method in two aspects of the theory and experiment confirmed the partially polarized through the Schmidt prism is still partially polarized light,but the two partially polarized are not the same.We research the measurement method of Jones matrix and Mueller matrix of the optical element. Jones matrix and Mueller matrix of the Schmidt prism are measured, and the consistency between the matrix measured and the matrix from the theory prove that both of the method to measure Jones matrix and Mueller matrix are feasibility. The comparison between the two measuring method of Mueller matrix and Jones matrix show that the method for Mueller matrix is more complicated than he method for Jones matrix, so this article characters and measures the Polarization aberration of Pechan prism with the help of Jones matrix.According to the special structure of Schmidt prism, on condition that linearly polarized light vertical incidence after Schmidt prism, according to the contrast of the light polarization tracing Jones matrix would be got from two path, it was found that Jones matrix of the two path had the same main diagonal, vice diagonal differ π phase characteristics. Therefore, it is only necessary to measure matrix of one swing; And according to the matrix knowledge, as well as the role of the expression of matrix factor in polarization diffraction light intensity, it was found that only the amplitude factor (namely the B factor) is independent of the Jones matrix four factors of Schmidt prism. Therefore, the measurement of Schmidt prism Jones matrix is just factly the measurement of a amplitude factor and two phase factors. Three different Schmidt prism samples were measured in the experiment; Jones matrix of the three samples has been got. The experiment verify that when the B= 0, the conclusion that there is no polarization aberration in Schmidt prism is correct.Considering the intuitive of polarization aberration measurement and characterization of Schmidt prism, the experimental system to measure diffraction spot was built, it was found through the experiment that:the zero level spot of bare prism with no coating was divided into two disc, it was dark in the center area; prism with general coating has also spitted, but it was weak than bare prism; there is a complete no-split airy disk when prism with very good coating.The diffraction spot shoot was the same as the result of analysis of element diffraction light intensity distribution with Jones matrix.Finally, according to the uniqueness of the relationship between diffraction diagram and B factor. We write the calculate program that use the B factor draw the diffraction pattern. The interface can achieve arbitrary B factor, corresponding diffraction intensity distribution. Besides that, we also write a program to achieve the three dimensional intensity distribution by the diffraction pattern.At this point, Pechan prism of polarization aberration distribution can be measured and characterized more intuitive not only by diffracted light intensity, but also by Jones matrix factor, which can meet the needs of measurement and correction of polarization aberration.