Investigation On The Generation, Propagation Of Partially Coherent Beam And The Self-healing Property Of Beam

In recently several decades, the unique properties of partially coherent beams attract more interesting of people. It can be applied to material processing, inertial confinement fusion, free space optical communication, optical trapping, optical image and so on, hence more attentions are put to the study of partially coherent beam. In this thesis, we introduce the generation of partially coherent beam and its propagation properties after being modulated. In addition, the self-sealing of beam is also introduced.Coherence, polarization and phase are the fundamental properties of light. They are not independent with each other, but interact with each other. How to easily, quickly and exactly control them is a meaningfull thing. In this thsis, we research the propagation property of light beam after being modulatied thier coherence, polarization and phase. In detailed, we studied the statistical property of scalar and vector partially coherent beam after passing through a phase aperture propagating in free space. We studied the polarization of a vector partially coherent beam after passing through a polarization grating propagating in free space. These results show that the phase apture and polarization grating can be used to modulate the coherence and polaztion of beam, hence they can be used to shape the beam profile. These results may be applied to optical traping, material processing. We also studied the statistical property of radially polarized partially coherent beam propagating in free space after passing through a lens. The result shows that the state of polarization of radially polarized partially coherent propagating in free space is not change. Coherence can be used to provide more information about light beam, hence we studied the detection of the rough target in turbulent atmosphere by using a partially coherent beam. Our results may be applied to remote senceing and image.The evolution of degree of coherence for partially coherent beam in free space is studied. Degree of coherence can be understood as the second order correlation of field. However, there is little report on evolution of the correlation of intensity fluctuations. We explored the evolution of the correlation of intensity fluctuations of a vector partially coherent beam in free space. We found the evolution of the correlation of intensity fluctuations is more complicated than that of degree of coherence and therefor the research results can make people deeply understand the property of partially coherent beam. We also studied the correlation of intensity fluctuations in far zone generated by a quasi-homogenous source. We found the relationship between the correlation of intensity fluctuations in far zone and the spectrial density in source plane. Our result shows that one can reconstruct the spectrial density in source plane by measuring the correlation of intensity fluctuations in far zone.In addition, we have studied the self-healing property of Bessel-Gaussian beam that belongs to the diffraction free beams both experimentally and numerically. Our results clearly show that the self-healing ability of the radially polarized Bessel-Gauss beam indeed is superior to that of one order linear polarized Bessel-Gauss beam, and some physical interpretations are given. Our results will be useful for particle trapping and microscopy.