基于图像处理的频域有限差分法用于实际光子晶体光纤的研究

提出了一种基于图像处理算法和频域有限差分法相结合研究实际光子晶体光纤的数值分析方法.该方法针对实际光子晶体光纤由于结构不规则难以进行数值分析的缺点.采取首先对光子品体光纤的电镜扫描图像使用阈值分割和维纳滤波等图像处理算法获得光纤截面的几何网像.然后使用图像插值及构造均值移动窗口滤波等方法实现了网格划分和介电系数平均等步骤,最后结合频域有限差分法对光纤特性进行分析计算.结果表明,该方法能够精确分析实际光子晶体光纤的色散特性.模拟得到的实际光子晶体光纤的模场分布与实验结果吻合很好.

Analysis of Real Photonic Crystal Fibers by Finite-Difference Frequency Domain Method Combined with Digital Image Processing

A finite-difference frequency-domain method combined with digital image processing is used to analyze real photonic crystal fibers. To overcome the difficulties imposed by the irregularity of the fiber cross section, the fiber structure is first obtained from the scanning electron microscopy (SEM) image of a real photonic crystal fiber by such digital image processing techniques as thresholding segmentation and Wiener filtering. Image interpolation and window filtering method are then employed to realize mesh division and permittivity averaging. Parameters obtained above are used in fiber property analysis by the finite-difference frequency-domain method. It is shown that the proposed method gets accurate fiber dispersion compared with measurement, and also that the calculated mode field distributions correspond well with those recorded in the experiment.