| Optical vortices are intriguing special optical structures with helical (or spiral)wave fronts, which attract much attention for their well-defined orbital angularmomentum(OAM) properties. This kind of special optical field has been applied inmany fields that include optical micromanipulation, atomic optics, biomedicine,nonlinear optics, or quantum information processing. In this thesis, we explored thegeneration mehtods of optical vortices, their diffractive properties and applications.The major content and result are as follows:1. We made a description of optical vortices, introduced some method to generateoptical vortices and analyzed the angular momentum of the optical vortices underparaxial condition.2. We analyzed the vortex properties of the field generated by multi-level stepspiral phase plate, and gave the condition for generation of optical vortices withmaximal OAM, minimal OAM and high purity, which provide us some usefulparameters for designing the spiral phase plate and its applications.3. We explained the relationship between modulation depth of optical vortices andthe phase deviation of the spatial light modulator in theory. This theory provide apossible approach to measure the phase deviation of SLM.4. We analyzed the properties of the helical phase spatial filtering system andproposed a new method to generate optical vortices with any shape and array byuse of helical phase spatial filtering. This method offers an advanceduser-interactive functionality and high adaptability, which are important forapplications in study of optical micromanipulation of a mixture ofmicrostructures, optically induced photonic lattices, and lattice of optical vortexsoliton.5. We introduced a new method to implement radial Hilbert transform by use oflaguerre-gaussian spatial filters and demonstrated the feasibility of this method intheory and experiments. The result implied that using this method can enhancethe edge information of the image effectively and advanced the contrast. |
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