Partially Coherent Light Transmission Characteristics In Turbulent Flow And "ghost" Imaging Studies

Coherence is one of the most fundamental properties of the electromagnetic field. Partially coherent light field has the characteristics of uniform distribution of light intensity and transmission invariance through turbulence medium, which have attracted more and more attention and been applied in remote sensing, biological tissue imaging, nonlinear optics, free-space optical communications and ghost imaging. Based on the practical application of partially coherent beams and theoretical model of coherence, the propagation properties of partially coherent radial vector beams through biological tissues and the lensless ghost imaging with partially polarized GSM light through turbulence have been theoretically investigated and numerically simulated. The main innovations are listed as follows:Firstly, the analytic formula of the cross-spectral density matrix of the coherent radially vector field propagating in the biological tissue is deduced, and then the expression of the electric field intensity and the polarization characteristic after transmission is obtained. The intensity distribution of the radially polarized partially coherent beam keeps doughnut beam profile and the doughnut profile of beam finally converses into a quasi-Guassian beam profile through the turbulent biological tissue. Various biological tissues would influence the velocity of the hollow shape of the radially polarized partially coherent beam changed to a Guassian type beam,which depending on the size of the turbulent biological tissue outer scale. In addition,the polarization structure of the radially polarized partially coherent beam will be destroyed during propagation in a turbulent biologic tissue. The polarization structure of the radially polarized partially coherent beam will be destroyed faster in the far field with the coherence length of the light source decreases and the mean square of refractive index of biological tissue increases. The optical properties of the partially coherent radially polarized beams would be more significant influence by the structure of biological tissue compared to the coherence length of the light source. The findings may be useful in the investigation of the structures and tissue imaging.Secondly, the theoretical formula of the lensless ghost imaging with partially polarized GSM light through atmospheric turbulence is deduced. The degree of polarization of partially polarized GSM light source exert an influence on the imaging visibility and quality of ghost imaging is studied. The simulation results show that the polarization of the light source still affects the imaging effect of ghost imaging through atmospheric turbulence. In the scalar theory, The imaging visibility of lensless ghost imaging with partially polarized through turbulence is proportional to the correlation length of the light source, and the image quality is inversely proportional to the correlation length of the light source, so the visibility and quality are a contradictory parameter. We cannot obtain the image with the best quality. But we can control the degree of polarization of the light source to obtain a certain balance between the visibility and quality of imaging, and then obtain a better reproduction of the image.