基于组合包层的微结构光纤的色散特性

为了获得微结构光纤的平坦色散特性,设计了一种圆形排列的微结构光纤,其包层由周期分布的空气孔构成,通过有限元数值分析法对该微结构光纤基模的色散特性进行了数值仿真,研究了色散和纤芯圆孔尺寸以及波长的关系。结果表明:内外空气孔间距和直径对微结构光纤的色散曲线都有影响,但内包层大孔间距和第一圈小空气孔的直径对色散曲线的走向起决定作用。在内圈空气孔直径为3.1μm,其他空气孔直径为1.0μm,内圈空气孔中心间距为5μm,其他空气孔中心间距为4μm时,光纤在1.3μm波长的色散为19.5ps/(nm·km),在1.6μm波长的色散为26.5ps/(nm·km),在1.3～1.6μm波长范围内,其色散值变化范围为7ps/(nm·km)。

Dispersion property of composite cladding microstructure fibers

In order to analyze the flat dispersion properties of microstructure fibers, a microstructure fiber with a circular arrangement is designed, the cladding of which consists of periodically distributed air holes. Its dispersion property is numerically simulated by using the finite element numerical analysis method and the dependence of dispersion on the size of the circular holes of the core and wavelength is investigated. The results show that the spaces between the inner and outer air holes and diameter both affect the dispersion curve, but the space between the big holes in the inner cladding and the diameter of the first circle of small air holes play a decisive role in the curve trend. When the diameter of the inner air holes is 3.1 μm and those of the others 10 μm, and the space from center to center of the inner air holes is 5 μm and those of the others 4 μm, the dispersion is 19.5 ps/(nm·km) at the wavelength of 1.3 μm and 26.5 ps/(nm·km) at the wavelength of 1.6 μm, and the dispersion varies in the range of 7 ps/(nm·km) in the wavelength range of 1.3～1.6 μm.