Research On Transmission Characteristics And Application Of Novel Dual Core Fiber

The dual-core fibers show us an amazing and promising application potentiality for their special properties, such as high dispersion property, coupling effect. In recent years, the design, fabrication and application of dual-core fibers have become hot research tropics. Especially, the application researches based on the dispersion compensation of dual-core fibers have been paid more and more attention. At the same time the research which is taken advantage of slow and fast light of coupled structure also attracted attention. From the analytic perspective, the design of parallel-dual-core fiber with high negative dispersion for dispersion compensation and the application in the field of slow and fast light are studied theoretically. The main achievement and contents are as follows:1. The development of the current dual-core optical fiber and technical characteristics are summarized. Dual-core fibers include the traditional dual-core fibers and dual-core photonic crystal fibers which are the current research focus. The article describes the characteristics and applications of both the fibers in the development of optical fiber communication systems and analyzes their advantages and disadvantages.2. A novel optical fiber device with a very high dispersion value is designed.Based on the step optical fiber characteristic equation, the effective refractive indexes of independent guide modes are obtained. And coupling coefficient, group refractive index of supermodes, group velocity dispersion, and the third order dispersion with different spacing between two cores and different diameters of two cores are obtained by the mode coupling theory, respectively. The results show that at the phase matching wavelength of 1550 nm, the higher dispersion is obtained. Through numerical calculation of the structure parameters including two and three order dispersion of the super modes with different distances between the two cores, different dual-core diameter, the results show when at the wavelength of 1550 nm, the diameters of the two cores are 310nm,640nm, respectively, the spacing between dual cores is 1.3 nm, and two order dispersion can reach -9.7794×105 ps/km.nm.3. The application of the dual-core fiber in the field of slow and fast light is studied in detail. Based on the formula which is about the delay or time-out caused by the transmission of the light pulse in the fiber and the refractive index difference (super modes as opposed to independent guided mode) of the coupling structure, the relative index difference affected by the structural parameters under different conditions is analyzed. When we ensure that the pulse broadening factor is no more than 2,The dual fiber with a length of 3.6mm can be speed up or slow down 2ps pulse to 6.6ps.