Dispersion-compensation optimization for dual-concentric-core photonic crystal fibers

• Main Authors: I-Hung Tsai, 蔡一弘
• Other Authors: Jui-Ming Hsu
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/57264702089583601545

碩士 === 國立聯合大學 === 光電工程學系碩士班 === 99 === In optical fiber communication systems, the dispersion coefficient of transmission single-mode fibers is positive. In the process of optical transmission, chromatic dispersion in fibers causes pulse broadening which is a principal cause of misdiagnosing a data level. In optical fiber transmission systems, people may insert a length of dispersion-compensating fibers, which bring about a negative dispersion coefficient, to neutralize the positive dispersion of transmission fibers. Accordingly, the negative effects of pulse broadening can be significantly reduced. Dual-Concentric-Core Photonic Crystal Fiber (DCC-PCF) has superiority for dispersion management. Previous DCC-PCFs are made up with a single-layer outer core ring. In this thesis, by taking advantage of the peculiar characteristics of DCC-PCF about dispersion, we set about an optimization study for dispersion-compensating photonic crystal fiber using DCC-PCFs with multi-layer outer core ring. First of all, we investigated some influence factors for the dispersion of DCC-PCFs, e.g. a pitch Λ (center-to-center distance between the holes), air filling fraction, a diameter of the holes of outer core rings (dc), and the layer-number of the outer core ring. The tailor-tendencies of these factors with dispersion can be generalized. Then according to the tailor-tendencies, we can design a DCC-PCF with maximum value of negative dispersion. Numerical results show that the negative chromatic dispersion coefficient for the designed multi-layer DCC-PCF is about -10500ps/(km-nm), which is approximately 1.36 times greater than that of the optimized single-layer DCC-PCF, at around a wavelength of 1.55μm.