Mode Property Of Chiral Photonic Crystal Fiber With Three/Four Cores Based On Triangular Lattice

With the explosive growth of demand for information, the fiber-based optical network has gained rapid development. The capacity of the traditional single-core single-mode fiber system has reached its physical limits already. To solve this problem, people are trying to develop new type of fibers such as few-mode fiber(FMF), multicore fiber(MCF) and photonic crystal fiber(PCF) and so on. It is an important trend to study fibers suitable for long-haul and low-loss transmission on the basic of new materials, new structures and new mechanisms. Due to the low attenuation and large effective mode area, PCF has been found wide application in different fields of production and life. As a new kind of material different from ordinary ones, chiral medium can be employed to design innovative fiber. Up to now, people rarely study the dielectrically chiral multi-core PCF. It is believed that our research may make a contribution to the new type of fibers.In this thesis, based on Maxwell’s equations and the constitutive relations for chiral medium, by considering the case of 2D photonic crystal and using the modified plane-wave expansion method suitable for chiral case, the problem to solve the mode of chiral PCF is converted to the problem to solve the eigen-solutions of a wave equation. The characteristics of mode fields are investigated for chiral multi-core PCF.Under three different parameters we firstly simulated the intensity distribution and polarization distribution of the non-chiral photonic crystal fiber with three cores, as well as four cores. The influence of core diameter and the core distance are analyzed on the intensity distribution, polarization distribution and the effective area of mode field. Then, by introducing the chirality into the core as well as the background, the influence of chirality is studied on mode characteristics. We also found all pairs of modes meaning they possess the same intensity distribution and the opposite polarization distribution.At the last, we studied the change in mode properties when the microstructure is introduced in core of the PCF with only single core, three cores and four cores, and analyzed the effect of microstructure on mode characteristics.