The Flatness Characteristics Analysis Of Double-mode Dispersion In Photenic Crystal Fiber

Photonic crystal fiber (PCF) is a new kind of transmission fiberwas developed on the foundation of photonic crystal technology. Forits greater and designal degrees of freedom, it owns more advantagescompared with the traditional optical fiber, such as HighBirefringence, Large Mode Area, the Zero dispersion after ShortWavelength, the Endless single mode property, High Optical nonlinearand so on. These made Photonic crystal fiber own importantacademic value and broad application prospect in the field of opticalcommunications and ultrafast lasers and so on.At present, the dispersion research of Photonic crystal fiber ismainly concentrated on the PCF of the fiber core with an air holedefect, and also seldom on the PCF of the fiber core with seven airhole defect. This paper has adopted the model calculation method ofeffective refractive index, while made theoretical simulation on thecladding effective index of photonic crystal fiber, the propagationconstant, the effective normalized frequency, and as well as ondispersion coefficient by using the computer language program ofMATLAB, meanwhile, and which puts emphasis on the analysis of several structural parameters which should be influenced by theirchanging. Finally, by changing the structural parameters of photoniccrystal fiber, we worked out the photonic crystal fiber which meetsthe needs of both fundamental model and seven air hole defect of thefiber core structure on O wave band、visible spectrum and S、R waveband, respectively.