Analysis Of High Nonlinear Characteristics Of Sub-micron Structure Photonic Crystal Fibers

Photonic crystal fiber (PCF) based on its flexible adjustablestructure can get variety of characteristics that traditional fibercannot appear. For example zero dispersion, flat dispersion, highbirefringence, highly nonlinear. It has gradually become the currentstudy hotspot. Highly nonlinear photonic crystal fiber have a widerange of applications on optical fiber communication devices,wavelength changes by stimulated Raman scattering, pulsecompression and phase modulation and other fields. Highly nonlinearphotonic crystal fiber has important values on the theoretical andpractical application. Now days the research on photonic crystalfiber’s characteristic focuses on the order of microns, and get a lot ofvaluable results. But research on its properties, especially highnonlinear structural parameters for submicron, is relatively little, stillneed intensively basic research for practical application.Photonic crystal fiber characteristics and several commonanalysis methods are briefly introduced. Corresponding discussion ofthe two types light guide mechanism of photonic crystal fibers arealso introduced. Two types light guide mechanism are photonicband-gap guided and total internal reflection guided. Introduced the current research status and achievements to the research direction.Fiber characteristic equation is obtained from the Maxwell equations,using the full vector effective index method derived the effectiverefractive index and the propagation constant. Mechanism nonlineargeneration and several nonlinear effects produced in the fiber areintroduced. Hexagonal air hole micro-structure as example, in thesub-micron order of magnitude in the structural parameters, thispaper intensively studied the effective refractive index as a functionof wavelength, obtained the effective mode area, and the nonlinearcoefficient versus wavelength. Using Matlab program, the variation ofeffective mode area and nonlinear coefficient with wavelength indifferent parameters have been obtained, higher nonlinear coefficientwith different structural parameters have been obtained in the visible,near-infrared band, O-band, and S-band.