Analysis Of Sub-micron Photonic Crystal Fiber's Disperse Property

Modern optical fiber technology is great successful in the twentieth century, and become our first choice to transfer information. Because of its long-distance and high-speed advantages, it has been considered as the crux in the communication area. In other areas, Fiber-optic technology also has been used widely, for example, in medical, machining and sensor detection and so on.But so far, the transmission speed of the optical fiber is significantly lower than the capacity of itself. This is because that the optical signals in optical fiber are restricted by two factors: loss and dispersion. The emergence of dispersion is mainly due to that different wavelengths possess different transmission speeds in the same medium, so it is essential for us to think how to remove the dispersion through our research. Photonic crystal fiber (PCF), which appeared just nearly ten years, shows a lot of wonderful characters compared with traditional optical fiber. Such as, endlessly single mode property, adjustable dispersion property, great optical nonlinearities and so on. It has gradually shown a very important role and bright prospects for the development of the optical communication system, We will give a brief introduction to the structure, light-guide mechanism principle, research methods of PCF.However, the research of PCF mainly focuses on the structure parameter within the magnitude of micron, while the various characteristics of sub-micron structure PCF have not been discussed at present. This paper mainly discussed that how to use the Effective Index Method analyzing PCF and investigating the cladding refractive index of the sub-micron structure PCF. Secondly, based on the Effective Index Method, the disperse characteristic of sub-micron structure PCF is analyzed, and giving the properties how dispersion changes with wavelength and cladding structure parameters. According the result we derived, designed some kinds of sub-micron structure PCF, which have near-zero dispersion and flat dispersion in the visible light band and optical communication band. Finally, some transmission characteristics of sub-micron structure PCF were studied, such as endlessly single mode property and number aperture. In this section we also analyzed the variation rules of the properties with the change of the structure.