Research On Transmission Characteristics And Applications Of Doped Photonic Crystal Fibers

We study characteristics of doped photonic crystal fibers (PCFs) by using full vector finite element method in this paper. In the work, the effects of every structure parameters of the doped-core photonic crystal fiber on dispersion and nonlinearity characteristics are studied and analyzed. And we study theoretically a hybrid-core photonic crystal fiber with high nonlinearity and flattened dispersion. The main study contents are as follows:1. The transmission characteristics of the bismuth-doped core photonic crystal fiber are studied in theory. The nonlinear coefficient of the PCF is improved and the dispersion property of the PCF is also changed after the fiber core is doped with high refractive index material. We study theoretically the effects on dispersion and nonlinearity characteristics by varying the diameter and refractive index of the doped-core and the air-hole diameters and lattice constants. And the results of the study will guide us about the structure design of the PCF with high nonlinearity and unique dispersion property.2. We propose a hybrid-core photonic crystal fiber with nearly-zero flattened dispersion and high nonlinearity. The hybrid-core of the photonic crystal fiber consists of two bismuth-doped materials with high refractive index. So this design structure will not only largely improve the nonlinearity of the PCF, but also can control the profiles of the dispersion curves. We will obtain the PCF with nearly-zero flattened dispersion and high nonlinearity in the telecommunication window by analyzing the effects of the structure parameters on dispersion and nonlinearity characteristics. In the optimized structure parameters of the PCF, the dispersion value is about0.5537ps/(nm-km) and the nonlinear coefficient is up to3301W-1km-1at1.55μm. And we achieve a flattened dispersion profile fluctuating between0.57ps/(nm-km) and-1.93ps/(nm-km) over a wavelength range between1.496μm and1.596μm.