Structure Design And Dispersion Of Hollow-Core Photonic Bandgap Fibers

Hollow-core photonic bandgap fiber (HC-PBGF) provides a new mechanism for light guidance due to its photonic bandgap, and the hollow-core photonic bandgap fiber is also widely used in optical communications and optical devices. Meanwhile photonic bandgap fiber possesses characteristics that traditional optical fiber does not have such as dispersion controllable ,coupling and nonlinear et ,especially the dispersion controllable has become one of the important areas in study. Structure design and dispersion are analyzed in this paper , and study the influences for dispersion with variations of fiber's structural parameters. We design a mixed structure hollow-core photonic bandgap fiber, and this fiber not only has low dispersion but also has high power transmission in core. And it also provides new contents for the design of hollow-core photonic bandgap fiber.Firstly, we introduce the background of photonic crystal fiber, mainly focuse on the applications and classifications of photonic crystal. Then we introduce the mechanism of guidance for photonic crystal fiber, and analyze the characteristics of the total internal reflection photonic crystal fiber and photonic bandgap fiber. We design a square-lattice hollow-core photonic bandgap fiber by reducing air-holes of the first ring , and analyze the dispersion,effective mode area,power in core of the fiber. The results say that the square-lattice hollow-core photonic bandgap fiber can realize low dispersion , and provides theoretical basis and reference for designing of hollow-core photonic bandgap fiber.Then, we analyze the influences of parameter variations for dispersion of hollow-core photonic bandgap fiber with hexagonal air-holes. When the hole-space and diameter with curved turn increase ,the zero dispersion point moves to long wavelength .But as the diameter of holes increase ,the zero dispersion point moves to short wavelength ,and this can provide theoretical reference for designing of hollow-core photonic bandgap fibers.At last we design a mixed structure hollow-core photonic bandgap fiber,and obtain low dispersion and good power transmission in core. Then we contrast the mixed structure hollow-core photonic bandgap fiber with square-lattice hollow-core photonic bandgap fiber ,roundness air-holes hollow-core photonic bandgap fiber and hexagonal air-holes hollow-core photonic bandgap fiber, and further confirms the excellent transmission of mixed structure .The mixed structure HC-PBGF has low dispersion and high power transmission in core , and it has potential applications in soliton transmission , pulse compression and WDM.