Theoretical And Experimental Study Of The Generation Of Vortex Beam By Computer Generated Holography

Vortex beams are new type of beams. Vortex beams have many potential applications,especially in optical tweezers and optical rotation technology, because the ring distributionof light intensity and the internal orbital angular momentum. Therefore, it was studiedactively recent years. Many creation methods of vortex beams were designed. In thesemethods, the computer generation holography was studied more because it has manyexcellences. For example, the theory is simply, utilization of beam is high, and it is easy toobtain the special beam that we need. In this thesis, we studied the computer generationholography to create the vortex beams. The major contents and results are as follows:Firstly, Outlined search back ground, history and present application of computergeneration holography in create the vortex beams. Then the vortex beams and applicationsin optical tweezers and optical rotation technology are summarized.Secondly, the theory of the computer generation holography and it’s advantages inmodify the mode of laser and in optical analysis were discussed. A few methods based oncomputer generation holography to created different vortex beams were expatiated andanalyzed in detail. And the characters and applications of these vortex beams were alsodiscussed. Based on the computer generation holography theory and by encating theparameters, the interference patterns of vortex beams with plane wave were numericalsimulated by MATLAB program.Finally, three different gratings were made by films, which record the computergeneration hologram. One is integer and fractional orders fork-like gratings. One isholograms that record the phase of vortex beams. The other is the gratings that cangenerate vortex beams with two vortex cores. The theory of gratings to generate vortexbeams was analyzed and calculated, theoretically. The experiments were designed and didin the later. And the results of experiment were discussed. The problems of theexperiments were analyzed. Then recommendations and suggestions were made toimprove the experiments.