Theory Study Of Nonlinear Optical Transmission Characteristics On Submicron Chalcogenide Waveguide

Chalcogenide waveguides are combination the good mid-infrared permeability ofchalcogenide glasses and the unique transmission characteristics of optical waveguides.Application prospects in nonlinear optics and other fields of chalcogenide waveguides areextremely broad. Therefore, theoretical and experimental research in the field of nonlinear optics ofchalcogenide waveguides has become the hot topic for domestic and foreign.In this thesis, we selected chaocogenide glasses as a host for waveguides, and researched thestructural and nonlinear transmission characteristic of the optical waveguides. Our researches arefocused on the relationship between the group velocity dispersion, single mode, effective modeareas characteristics and structural parameters of waveguides. By optimizing the waveguidestructural, we explored the nonlinear transmission characteristics of ultra-short pulses inchalcogenide optical waveguides. The broadening mechanisms of supercontinuum of ridgewaveguide were systematic researched. By optimizing the waveguide length and pump power, wetheoretically achieved a wide and flat supercontinuum. The thesis was arranged as follows:The introduction of this paper briefly described the material properties of chalcegenide glasses.Dispersion and several kinds of nonlinear effects in optical waveguides were analyzed simply. Andwe described the status of the application of nonlinear propagation properties of chalcogenide hostwaveguides. And the problems and deficiencies in previous work were analyzed. Finally, theresearch purpose and content of this thesis were put forward.In chapter two, we introduced the theory of waveguides and pulse transmission, and theanalysis method of waveguides structure. Theoretical analysis method of finite difference methodand the effective refractive index of optical waveguides were introduced in detail. According toMaxwell’s equations, nonlinear Schr dinger equation of pulse propagation in the waveguide wasderived.In chapter three, we introduced the split-step Fourier algorithm of the numerical solution ofthe generalized nonlinear Schr dinger equation. Based on this algorithm, we detailed thesymmetric split-step Fourier algorithm principle in solving the application of optical pulsetransmission equation.In chapter four, the relationship between dispersion characteristics and waveguide structureparameter were studied systematic with the finite difference method. On the basis, we also analyzed the relationship between the effective area and structural of waveguide. Using effectiveindex method to simulate and analyze the waveguide structural for single-mode transmission.Based on the above findings, we could select submicron ridge waveguide structure with the highnonlinear parameters.In chapter five, according to the generalized nonlinear Schr dinger equation, we analyzedsupercontinuum generation of ultra-fast pulse in highly nonlinear submicron ridge waveguide withnumerical simulation. Comparing the characteristic of the pulse transmission in the normaldispersion and anomalous dispersion waveguides. The effects of various parameters onsupercontinuum broadening were analyzed generally. When the optical waveguide located in theanomalous dispersion region, the effects of pulse width, pump power, initial chirp and ridgewaveguide length on shape and spectral properties of supercontinuum were discussedsystematically. Optimizing the parameters, the bandwidth about800nm of supercontinuumbroadening was obtained.The finally chapter summarized the thesis, and noted out the insufficient of the research forimprovement and the areas for further research in the future.