Propagation Dynamics Of Spatial Optical Soliton And Applications And Test Of Diffractive Optical Elements In "Shen Guang" Device

The dissertation is supported by the National Natural Science Foundation of China under Grant No. 10274078 and military 863-804 research Foundation. It includes two parts: Part I Propagation dynamics of spatial optical solitons, and Part II Applications and test of diffractive optical elements in "Shen Guang" device.The contents and conclusions of Part I are as follows:1. The interaction of two optical vortices with opposite topological charges in a linear medium is investigated in theoretically by Nonlinear Schrodinger equation and the interaction of the vortices is investigated numerically by step-by-step Fourier method. An instability resembling Symmetry-Breaking instability happens when the vortices carry opposite topological charges. The screw phase dislocations evolve into a new type dislocation—edge phase dislocation with the optical field propagating. The sum of the topological charges conserves in the whole process. As linear media diffraction effects of a stronger, the vortices in the dissemination of certain distance from the diffraction effects will become apparent.2. First, we designed a computer-generated holographic grating and have used two kinds of recording mediums -holographic plate and-to manufacture this holographic grating. Laguerre-Gaussian (LG) modes with topological indices from the lowest to higher order have been observed in the experiment. We also noticed the higher order modes are spatial unstable. Second, the related controlling parameters, such as the exposed time and intensity which influence the diffraction efficiency, are discussed in detail. At last, We design a fork-like grating to measure the superposition of two LG modes. It is useful in the high-dimensional quantum communication.3. Design and production a holographic grating that can have with two Laguerre-Gaussian mode carrying opposite topological charges. The interaction of two Laguerre-Gaussian mode carrying opposite topological charges in a linear medium is investigated experimentally. The changes of diffractive pattern are observed when these two LG mode propagate, a dark arc happens in the center dark particle of two LG mode when the interaction of two LG mode carrying opposite topological propagates in a linear medium. This experiment phenomenon proves that the screw phase dislocations evolve into a new type dislocation—edge phase dislocation with the optical field propagating.The contents and conclusions of Part II are as follows:1. In the field of resolving the "uniform illumination" problems, we introducing a new algorithm based on iterative optimization which used for designing diffractive optical elements (DOE). This method of design saves the computing time tremendously.2. The adaptability of the diffractive optical elements (DOE) fabricated by steps technology in the practical system is studied. The effects of the random etching errors by ion beam multiprocessing steps technology, uncoaxial system and allocation of focal plane on the uniform illumination have been simulated. The result shows that this kind of DOE has huge adaptability, and some helpful parameters have been provided for test of engineering.Highlights of dissertation are follows:1. We have used two kinds of recording mediums -holographic plate and ink-jet transparent film-to manufacture the holographic grating designed by computer-generated holographic (GCH) method. Laguerre-Gaussian (LG) modes with topological indices from the lowest to higher order have been observed in the experiment .We also noticed the higher order modes are spatial unstable. Furthermore, the related controlling parameters, such as the exposed time and intensity which influence the diffraction efficiency, are discussed in detail.2. The interaction of two Laguerre-Gaussian (LG) mode carrying opposite topological charges in a linear medium is investigated experimentally. The changes of diffractive pattern are observed when these two LG mode propagate, a dark arc happens in the center dark particle of two LG mode when the interaction of two LG mode carrying opposite topological propagates in a linear medium. This experiment phenomenon proves that the screw phase dislocations evolve into a new type dislocation—edge phase dislocation with the optical field propagating.3. The adaptability of the diffractive optical elements (DOE) fabricated by steps technology in the practical system is studied. The effects of the random etching errors by ion beam multiprocessing steps technology, uncoaxial system and allocation of focal plane on the uniform illumination have been simulated. The result shows that this kind of DOE has huge adaptability, and some helpful parameters have been provided for test of engineering.