The Design Of High Birefringence Photonic Crystal Fiber And Numerical Simulation

Photonic-crystal fiber (PCF) is a new class of optical fiber based on the properties of photonic crystals for its ability to confine light in hollow cores. Because of its special optical properties and the flexible structural design, PCF has attracted extensive attentions. High birefringence can be easily realized in PCF, which has an important application in designing fiber optic gyroscope, fiber sensing system and optical fiber laser and have important significance on implementation of all-optical network. In this paper, two kinds of PCF are proposed and their model field, birefringence and dispersion are studied by detail. The original jobs in research are listed as follow:In recent years, photonic crystal fiber(PCF) has become more attractive because of their unique properties, such as high birefringence and polarization maintaining, singular dispersion characteristics, high nonlinearity, surface enhanced Raman Effect, large mode area and so on. PCF is a kind of novel optical fiber structure, which has revolutionized fiber optics and attracted extensive attentions.First of all, research significance of the academic topic is clarified and the application prospects of photonic crystal fiber are discussed. Several commonly used methods which can simulate and calculate the model field characteristics of PCF are introduced and contrasted. This chapter highlights the principle of the finite element method for PCF and as well as the application steps of related software.Secondly, the mode characteristics of PCF with asymmetric hexagon disposed cladding air holes are analyzed by the finite element method. The effect of structure parameters on model birefringence of the PCF is numerically studied and the dispersions of two orthogonal polarization of fiber are obtained. Meanwhile, this paper analyzes the cause of the simulation results and the parameter design structural optimization is implemented on the PCF.Finally, A new kind of highly birefringent index-guiding PCF with sectoral central symmetry cladding was proposed for the first time. By means of variational structure, the effective refractive index is gotten with solving the Poisson Equation of the PCF. Numerical value research discovered:The results shows that the birefringence of the fiber has been induced by asymmetries of both the core and the cladding. By adjusting the diameter ratio η(the ratio of internal diameter and external diameter) and the central angle0of the sector, it can effectively implemented for the adjustment of the birefringence phenomena and the value of birefringence reaches10-2order of magnitude. When λ=1550nm, the birefringence is4.8×10-2. At the mean time, flattened dispersion can be realized for wide wavelength range.