文中基于耦合模理论和简化的阶跃折射率单模光纤三层模型的包层模理论，提出了长周期光纤光栅的传输谱特性仿真的主要步骤及 matlab程序实现，为长周期光纤光栅的数值仿真提供了一种简便的方法-Text-based coupled mode theory and a simplified three-step-index single-mode fiber cladding mode theory model, proposed long-period fiber grating transmissio

计算阶跃折射率光纤传播常数、归一化频率、截止波长、导模数量等- Calculate for Step Index Fibers (using MATLAB): a) Propagation constant (β) b) Normalized propagation constant (b) c) V number (V) d) Check whether the fiber is single mode or multi mod