改进型蜂巢晶格结构光子晶体光纤的色散与非线性特性

The Dispersive and Nonlinear Properties of Photonic Crystal Fibers with Modified Honeycomb Lattice Structure

结合蜂巢晶格与不同空气孔直径晶格二者的优势,提出一种改进型蜂巢晶格结构光子晶体光纤,采用矢量光束传输法对该光纤的色散与非线性特性进行了数值模拟,分析了色散、非线性系数与其晶格参量之间的关系。数值结果表明,该光纤在1.2～1.6μm波段内可以实现大负色散、色散平坦、正色散等多种色散特性;此外,晶格结构中空气孔直径的减小使得基模有效面积增大,从而降低了非线性系数。因此,通过调节该光纤的结构参量可以灵活地调整其色散与非线性特性,为设计光子晶体光纤提供理论参考。

Photonic crystal fibers with modified honeycomb lattice structure were proposed by combining the advantages of honeycomb lattice and lattice with different air-hole diameters. The dispersive and nonlinear properties of the proposed fibers, which formed by different structural parameters, are numerically simulated by using the vectorial beam propagation method, and the relationship of dispersion, nonlinear coefficient with the lattice structure was investigated. The results indicate that the distinct dispersive properties, which contain large negative dispersion, flattened dispersion, positive dispersion, and so on are achieved in the wavelength range of 1.2 - 1.6 μm. Furthermore, the decrease of the diameters of air-holes in the lattice structure leads to an increase of effective area in fundamental mode which make the nonlinear coefficient lower. Thus the dispersive and nonlinear properties of the proposed fiber can be flexibly tailored by adjusting its structural parameters. This provides a reference for designing novel photonic crystal fibers.