The Research On The Way Of Detecting And Correction Of Polarization Aberration Of Pehan Prim

The Pehan prism is important ingredient of the telescopically optical system. By reason of its special structure,the incident light is splited as two path lights whose s component and p component intersect and change,and cause s and p component existing certain phase differences. Therefore it appear two elliptically polarized lights which have different azimuths on the same emergent plane. It is the polarization aberration. The research purpose of the paper is to find the way of correction and detecting of the polarization aberration and analyse the influence of polarization aberration on the telescopically optical system.The researchs of the paper include the following contents. The efficiency marix of Pehan prism was got by the Jones vector and the coordinate rotation matrix and then analyze the distribution of polarization state of the emergent wave,when linearly polarized light and light cone with certain angle pass the Pehan prism. And study the influence of lens on emergent polarization state,so the law of polarization aberration of the Pehan prism was obtained; According to obtained distributions of polarization state and light intensity of emergent plane,the influence of polarization aberration on image quality was acquired; By means of the analysis on the character of polarization aberration,the new method of detecting polarization aberration was gained; The method of correction was got by analyzing the reason of the polarization aberration of Pehan prism.The basic representation of polarization aberration is that there are two elliptically polarized lights which have different azimuths,when a bunch of lights pass two roof planes of Pehan prism. And the two azimuths have connection with the direction of vibration of linearly polarized light; The linearly polarized light that has the same incident angle and different direction of vibration enters the Pehan prism, two elliptically polarized lights were obtained on the emergent plane,but the included angle of azimuth is invariable. Only the direction of vibration of linearly polarized light is on special positon, the ellipticity of two elliptically polarized lights is equal; On the base of analyzing the distribution of polarization of emergent plane of Pehan prism,the core of the polarization aberration is phase difference that light passes respectively two roof planes.The representation of the influence of polarization aberration of Pehan prism on image quality is that image points were formed by the two emergent lights exists position difference. The experiment show that the image appears stretch on the image surface because of the polarization aberration of Pehan prism.On the base of the obtained character of polarization aberration,the new method of detecting polarization aberration was acquired. Because the core of the polarization aberration is phase difference,and the representation is focused on the included angle of azimuths of two elliptically polarized light. The extreme value of the sum and difference of light intensity was obtained to detect scheme of the polarization aberration. The model of measuring included angle of azimuths of the two elliptically polarized light was established. Using four quadrants detector detect the experiment,and contrast with Stokes parameter measurement. At last,the consistent preferably result was gained..The way of correcting polarization aberration:On the base of analyzing the reason of the polarization aberration,the core of the polarization aberration is phase difference. So the way was proposed that the phase layer was plated to correct the polarization aberration on the ridge of Pehan prism. Theoretical analysis and experimental result made clear that phase layer was plated on the roof of Pehan prism,which regards the phase difference of the two paths as a parameter,this method can eliminate the polarization aberration caused by the phases of the two paths.