mode_calc_using_FDM

代码说明：

说明：  计算光纤模场分布和传播常数，输入模式的阶数，计算得到各类模式的模场分布。直接运行main，在其中修改参数，至少可以计算5层光纤结构。(Calculation of optical mode field distribution and propagation constant, the order input mode, calculated by various types of mode-mode field distribution. Direct run main, in which the modified parameters can be calculated for at least 5 layer fiber structure.)