These modes fields can be used directly to the FD-BPM functional simulation of a waveguide device based on the same mesh grid and need not to find other methods to analyze the modes fields.

• 利用该方法得到的模场可以基于同一套空间差分网格而直接用于波导器件的FD-BPM功能模拟，避免为了分析波导模场而去寻求另外的方法。