空芯光子带隙光纤散射损耗特性及结构优化研究

Scattering Loss Analysis and Structure Optimization of Hollow-Core Photonic Bandgap Fibers

针对空芯光子带隙光纤内部结构提出了一种准确的建模方法,使用全矢量有限元法研究了纤芯结构变化对光纤散射损耗的影响,对不同纤芯壁厚度以及不同纤芯半径的空芯光子带隙光纤进行了仿真计算,并以归一化分界面场强表征散射损耗的大小。计算结果表明,纤芯壁相对厚度Tc≈4时,散射损耗可以得到较大的降低,同时散射损耗也会随着纤芯半径的增大而减小。通过对纤芯结构进行优化,理论上在1.5~1.56μm波段范围内散射损耗可比现有光纤减小50%。

An accurate modeling method for the internal structure of hollowcore photonic bandgap fiber is proposed, and the effect of core structure on scattering loss is studied by full-vector finite element method. The fibers with different core walls thicknesses and different core radii are simulated, and the normalized interface field intensity is used to characterize the scattering loss. Calculation results show that scattering loss can be largely reduced with the relative core wall thickness Tc≈4. Furthermore, scattering loss decreases with the increase of core radius. With optimized core structure design, the scattering loss can be further reduced down to 50% of the present level in theory within the wavelength range from 1.5 μm to 1.56 μm.